Kol Isha I: Halachic Basis

  • Deracheha Staff; Laurie Novick, Director
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How does halacha view song in general? What is of specific concern with kol isha? When and to which type of voice does kol isha apply?
Our voices, used in speech or song, are central to our identity as human beings. Onkelos emphasizes this in his interpretation of the story of Creation:
Targum Onkelos Bereishit 2:7
And Adam became a speaking soul
We use our voices in speech to communicate – not just to convey information, but to create emotional connections with each other. Raised in song, our voices can inspire and deepen our most powerful feelings, sweeten our daily routine, and praise our Creator. The prophets Devora and Miryam, for example, praise God through song:
Shemot 15:20-21
And Miryam the prophet, sister of Aharon, took the timbrel in her hand and all the women went out after her with timbrels and with dancing. And Miriam called out responsively to them: Sing to God for He has triumphed greatly, horse and his rider He has cast into the sea.
Shofetim 5:1,3
And Devora sang, and Barak ben Avinoam, on that day saying: ….I to the Lord, I shall sing, I shall sing out to the Lord, God of Israel.
As a prelude to our discussion of kol isha, halacha that limits men's listening to a woman’s voice, let's explore halachic limitations on song in general.
Constraints on Song
Songs have pride of place in the synagogue and at the Shabbat table. Even so, rabbinic texts indicate that Halacha does not view all song favorably. Especially following the destruction (churban) of Beit Ha-mikdash, restrictions were placed on certain types of song. Much of this halachic discussion centers on the songs' context, content and purpose.
I. Context  Singing is often an expression of joy, and our joy today is always tempered by the loss of Beit Ha-mikdash. In a prophecy foretelling destruction, Yeshayahu states:
Yeshayahu 24:9
They will not drink wine with song; strong drink will be bitter to those who drink it:
The mishna cites this verse to teach that we should no longer sing over drink, as at drinking parties or pubs, now that the Temple has been destroyed and the Sanhedrin disbanded.
Mishna Sota 9:11
When the Sanhedrin was discontinued, song was discontinued from places of drink, as it is said, "They will not drink wine with song."
The Talmud cites the same verse as a prooftext for banning song at drinking parties and the like in light of the churban, and brings a second verse to clarify that a cappella singing is included in the ban:
Gittin 7a
They sent to Mar Ukba: Song [Rashi: to sing at a house of feasting and drink] whence do we know it is prohibited? He drew a line and wrote to them: “Don’t make merry, Israel, to rejoicing among the nations” (see Hoshea 9:1).He should have sent from here, "They will not drink wine with song, strong drink will be bitter to those who drink it" (Yeshayahu 24:9). If from that, I might have said those words refer to instrumental song, but vocal [song] is permissible. This teaches us [that is not the case].
Especially in the aftermath of the churban, banning these types of songs expressed acute sorrow at the loss of Beit Ha-mikdash.
II. Content  Rif (in the name of a Ga'on) explains, however, that the prohibited vocal music refers specifically to love songs and not to songs of praise to God.
Rif Berachot 21b (Rif pagination)
A Ga'on explained: when we say vocal song is prohibited, these words refer to songs like those of the love of a person for his fellow and praising a beautiful person for his beauty…but words of songs and praise and mention of the lovingkindness of God, no person of Israel does refrains from this. And the custom of all of Israel is to say them in the houses of grooms and houses of drinking with the voice of melodies and voice of gladness, and we have not seen anyone object to this.
The Talmud Yerushalmi expands on why songs about human love or beauty raise rabbinic hackles:
Talmud Yerushalmi Sota 9:12
Mishna: When the Sanhedrin was discontinued, song was discontinued from places of drink, as it is said, "They will not drink wine with song."… Rav Chisda said: Originally, the fear of the Sanhedrin was upon them and they would not say vulgar words in song. But now that the fear of the Sanhedrin is not upon them, they say vulgar words in song.
The main concern, as expressed by the Yerushalmi, is not just that people immersed in song might lose sight of mourning the Temple, but that they might come to use inappropriate language. In general, desecrating the mouth with inappropriate language is prohibited.
Pesachim 3a
For Rabbi Yehoshua ben Levi said: A person should never let a disgraceful word leave his mouth.
In his Moreh Nevuchim, Rambam decries even composing songs that employ lewd or suggestive language as a misuse of the God-given faculty of speech:[1]
Moreh Nevuchim 3:8 (trans. Pines)
You know the severe prohibition that obtains among us against obscene language. This also is necessary. For speaking with the tongue is one of the properties of a human being and a benefit that is granted to him and by which he is distinguished. As it says: Who hath made man’s mouth? (Exod. 4:11) And the prophet says: The Lord God hath given me the tongue of them that are taught. (Isa. 50:4) Now this benefit granted us with a view to perfection in order that we learn and teach should not be used with a view to the greatest deficiency and utter disgrace…And whoever has applied his thought or his speech…so that he thought more about drink or copulation than is needful or recited songs about these matters, has made use of the benefit granted to him, applying it and utilizing it to commit an act of disobedience with regard to Him who has granted the benefit and to transgress His orders. He is like those of whom it is said: And I multiplied unto her silver and gold, which they used for Baal (Hos. 2:10).
III. Purpose  A further distinction between types of song emerges from the Talmud Bavli's discussion of the mishna about singing after the destruction of Beit Ha-mikdash
Sota 48a
Rav Huna said: the song of ship-tuggers and of cowherds is permissible, of weavers is prohibited…Rav Huna abolished song…Rav Chisda came and disregarded him…
Rashi Sota 48a
The songs of ship-tuggers – those who pull ships with a rope, [their songs are] permissible, because they are only to speed them in their work. And of cowherds – who sing when they plow, and it is only to direct the oxen in their furrows, as they walk to the sound of the song that is sweet to them. Of weavers – it is only for amusement.
Rav Huna distinguishes between songs sung for a specific practical purpose, such as to speed work along rhythmically, which he permits, and those sung merely for amusement, which he prohibits as incompatible with the mourning appropriate after the churban. Rav Chisda, on the other hand, allows both types of singing.
IV. Tzeniut  A final consideration, tzeniut, emerges from the continuation of the Talmudic passage about singing after the churban:
Sota 48a
Rav Yosef said: If men sing and women respond, it is immodest. If women sing and men respond, it is like fire to flax. What practical difference comes out from this? To abolish this [men answering women's song] before that [women answering men's song].
Men and women singing responsively is frowned upon here as immodest, with women taking the lead seen as particularly inflammatory. For this reason, Mishna Berura rules that men and women working together should not sing responsively with the women leading:
Mishna Berura 560:13
…In a factory, it happens that there are also men there, and [the women] sing and [the men] respond to them, it is like fire to flax and it is a great mitzva to abolish them [these songs].
Modern Application
Thus far, we have learned from these sources that we should all avoid singing in frivolous, wine-fuelled contexts and should favor songs with holy content, eschewing the vulgar or suggestive. Furthermore, because we mourn the churban, our singing should ideally be for a specific constructive purpose.
Today, Jewish communities are typically lenient about the restrictions on song related to churban. In a twentieth-century responsum, Rav Mordechai Ya'akov Breisch summarizes the halachic discussion around song, and considers aspects of its modern application, such as music over the radio:
Chelkat Ya'akov OC 64:2
…Who permitted the other matters mentioned in Shulchan Aruch 560 as forbidden due to mourning after the churban?… For all this is not practiced at all, and song on the radio, in any case one can rely on the approach of Rashi and Tosafot in Gittin, that it's only [prohibited] in a house of drink…and in Hagahot Mordechai at the beginning of Gittin, it is prohibited specifically at a drinking feast without eating, for that is the manner of the non-Jews, but at a feast with eating it is permissible … But if sometimes a woman’s voice is heard, or songs of desire and love, this is certainly prohibited and we need to be careful. And there is another major reason to permit, since at the time of the decree to forbid song due to mourning, there was not yet radio, so the decree does not apply to radio… for one cannot see the singer at all, and they come from far away through scientific innovation, which is considered a new entity that is not included in the decree…
Rav Breisch notes that many practices of mourning the churban have fallen out of practice, and people now sing more freely than they had previously. The ban on song over wine, however, seems still to apply to drinking that is not accompanied by a meal, or to song with suggestive content. These two restrictions remain firmly in place today, independent of current laxity with mourning practices.
In his responsum, Rav Breisch adds a new distinction between types of music. He explains that music on the radio is unlike live music, because of the distance between the music maker and the listener, and because our sages did not take the radio into consideration when making their decrees. This distinction should logically apply to other forms of recorded or electrically transmitted music.
Rav Breisch slips into his description yet another factor that he considers crucial, namely whether the voice singing on the radio is 'kol isha," the voice of a woman. Let's turn our attention now to exploring why that would be at issue and see how the discussions of context, content, and purpose regarding song in general relate to kol isha.
How can we relate to halachic limitations on music?
With the exception of concerns about kol isha and specific periods of personal or national mourning, accepted practice seems to be to listen to music, singing, and playing instruments without any particular halachic constraints or feelings of discomfort.
Indeed, many of the halachic practices associated with mourning the churban have fallen out of practice, with some degree of halachic sanction. In recent years, the explosion of technologies for producing and distributing music have made listening to music more and more a part of the average person's daily life.
Even so, treating kol isha as the only possible religious consideration involved in listening to music does a disservice to women and to Halacha. The halachot and customs that express reservations about music, especially music lacking tzeniut, raise broader questions that merit serious consideration.
How often does music in the background of our lives subtly affect our behavior, and in what ways? How many of us mindlessly stream or sing song lyrics we would never speak, because they come attached either to a catchy tune or to one that stirs our souls? Why do we act as though only women need to be thoughtful and modest about singing?
The religious imperative to be thoughtful about what music we listen to, why, and how goes well beyond the strictures of kol isha.
A Woman's Voice
Why should the way a woman chooses to use her voice be particularly sensitive?
Let’s begin with the speaking voice. In an extreme example in Sefer Shofetim, when the Canaanite general Sisera flees the forces Devora has marshaled in battle, Yael uses speech to convince him to take shelter in her tent:
Shofetim 4:18
And Yael went out to greet Sisera and she said to him, “Turn aside, my lord, turn aside to me, fear not,” and he turned aside to her to the tent and she covered him with a blanket.
The Talmud says that Yael aroused Sisera specifically with her voice.
Megilla 15a
Our rabbis taught: Rachav was promiscuous with her name, Yael with her voice…
Our sages understand Yael's speech as sensual, a prelude to her ultimate seduction of Sisera. Her conduct, which enabled her to kill Sisera and secure a full victory for the Israelites, receives special approbation as an "aveira li-shmah" (transgression for the sake of Heaven).  In general, though, deliberately arousing another with one's voice or words outside of the marital relationship goes against the principle of tzeniut.
We've seen that men as well as women should be careful about using the voice to arouse. Our sages give special attention to women's voices, though, perhaps because, as the Talmud notes (following Shir Ha-shirim), a woman's voice is on the whole considered uniquely pleasing when compared to a man's:
Nidda 31b
Why is a woman’s voice sweet, and a man’s voice not sweet?…As it is said, for your voice is sweet and your appearance lovely.
Rashi notes elsewhere that the same verse in Shir Ha-shirim establishes that a woman's voice can give rise to desire:
Rashi Berachot 24a
Your voice is sweet – from the fact that Scripture praises her for it, we learn that it is desirable.
A woman can employ the pleasing quality of her voice together with suggestive or intimate words to create an arousing effect – as Yael presumably did when speaking with Sisera. This may have contributed to our sages including flirtatious speech in their list of conduct in violation of the halachic category of dat Yehudit.
Mishna Ketubot 7:6
What is dat Yehudit?…and speaking with every man…
Ketubot 72b
And speaking with every man. Rav Yehuda said in the name of Shemuel: flirting with young men.
The Talmud does not specify whether the issue is the style, context, or content of a woman’s speech. This ambiguity makes some sense, since definitions of tzeniut may vary with each of these three factors, and dat Yehudit refers to the modest behavior that is customary for Jewish women:
Rambam, Mishneh Torah Ishut 24:11
What is dat Yehudit? The modest behavior that the daughters of Israel practiced.
All Jews are expected to act modestly. Still, behavior that violates dat Yehudit, such as using one's voice in inappropriately intimate conversation, is considered especially problematic for a married woman, regarding whom it may lead to suspicion of infidelity.[2]  
Kol Isha: Men's Prohibition
This background helps us to understand statements of the amora Shemuel that define a woman's voice as tantamount to erva, forbidden nakedness, from the standpoint of a man. In order to understand the implications of these statements for women, we need first to clarify what they mean.
A first passage, in Berachot,[3] takes the verse in Shir Ha-shirim as a prooftext for Shemuel's dictum.
Berachot 24a
Shemuel said: a woman’s voice (kol be-isha) is erva, as it is said: For your voice is sweet and your appearance lovely.
The verse emphasizes the unique sweetness of a woman's voice when she makes it heard to her beloved. The word for sweetness, "arev," even sounds like the word "erva."  More important, the verse compares a woman's voice to her looks, which helps explain how the voice can fit alongside other, visual examples of rabbinic-level erva listed in Berachot – such as a woman's thigh, which men may not look at freely – even though the voice cannot be seen.[4]
A second passage, in Kiddushin, applies Shemuel's statement to limit the exchange of greetings between a man and a woman.[5]
Kiddushin 70a
[Rav Nachman bar Yitzchak said:] Let the master [Rav Yehuda] convey [greetings of] peace to [my wife] Yalta. [Rav Yehuda] said to him: Thus said Shemuel: A woman’s voice is erva.
This dialogue is surprising, since Tanach and rabbinic literature contain many examples of male-female conversations. In the Talmud's example, Yalta, the woman whose voice is in question, is sexually prohibited to Rav Yehuda, perhaps suggesting that the exchange is prohibited as kol isha specifically when it might be construed as a deliberate approach to uncovering erva (forbidden relations). Rav Nachman himself, however, seems not to have seen anything wrong with his wife conversing with Rav Yehuda.
These Talmudic passages leave us with four essential questions about kol isha: When does the prohibition apply? To what type of voice does it apply? Does a man's intent make a difference? Is kol isha dependent on context? Taken together, these factors will shape the ways that women's voices are sounded in our communities.
Shema and Other Times
When does kol isha apply?
Shemuel's statement in Berachot appears in the context of a discussion of the prohibition for a man to see typically covered parts of a woman's body (classified as erva according to rabbinic law) during recitation of Shema. This halacha applies even if the erva does not in practice arouse the one who sees it.[6]
Halachic authorities disagree as to whether we should thus limit application of kol isha to when a man recites Shema or other prayers.[7] Mordechai quotes Rav Hai Ga'on, who does limit the application of kol isha in this way:
Mordechai Berachot 80
Similarly, a woman’s thigh or her voice are erva, and Rav Hai Ga’on explained that all these are for the matter of Keri’at Shema.
On this view, the discussion in Kiddushin about kol isha when sending greetings of peace might apply only to the exceptionally pious, and not to the common man.[8] The prohibition during Shema or prayer, though, could apply to hearing any woman whose voice might distract.
Disagreeing, in line with a more straightforward reading of the passage in Kiddushin, Rosh writes that the prohibition is not particular to the case of Shema.[9]
Rosh Berachot 3:37
Shemuel said: A woman’s voice is erva, as it is said, "For your voice is sweet," explanation: to hear [in general] and not [specifically] for the matter of Keri'at Shema.
Shulchan Aruch mentions kol isha both in the laws of Keri'at Shema (below) and in the laws of men's interactions with women prohibited to them.[10] His rulings suggest a global prohibition, with caution during keri'at Shema.
Singing and Speaking
To what type of voice does kol isha apply?
Halachic authorities discuss two different types of voice to which the halacha of kol isha may apply: the singing voice, which is considered especially arousing, and the speaking voice employed in a way that could lead to excessive familiarity. Ra'avad, cited by Rashba, lays this out:[11]
Rashba Berachot 24a
…"With his wife and during Keri’at Shema." Ra’avad explained…. Her face, hands, and feet, and her speaking voice that is not singing, and her hair outside of her hair-binding, which isn’t covered – we are not concerned about them because he is accustomed to them and not perturbed, and for another woman [not his wife], it is prohibited… to hear even her speaking voice, as we say in Kiddushin 70a, “Let the master [Rav Yehuda] convey [greetings of] peace to [my wife] Yalta. [Rav Yehuda] said to him: Thus said Shemuel: A woman’s voice is erva.” Yet nevertheless, it seems to refer specifically to the voice of sending or returning greetings of peace, because there is an emotional connection…
A woman's ordinary voice, to which a man is accustomed and more or less inured, is not considered erva.[12] Less commonplace uses of the voice, such as the singing voice, are. We are especially concerned about potential arousal during Shema or prayer. Therefore, the prohibition of hearing a woman's singing voice could apply at those times even to a man who hears the singing of a woman permitted to him, such as his wife.
Ra'avad expresses an additional concern – that a woman’s voice can create emotional connection, kiruv da'at. This should be avoided between a man and a woman to whom relations are prohibited as erva (such as a when the woman is married, or a single woman in nidda,[13] though exceptions are made for dating). On his view, a man may not listen to a woman's voice used in a way that builds or demonstrates kiruv da'at, which can be a problem of context or of content.
Aruch Ha-shulchan explains that kiruv da'at is specific to speech and does not refer to regular conversation, but to speech that fosters affection. He then specifies that the prohibition of kol isha generally applies to a woman's sweetened, or singing, voice, which a man enjoys:
Aruch Ha-shulchan EH 21:8
The prohibition is only for greetings of peace, which involves emotional connection and affection…for ordinary speech was not prohibited, but only the sweet voice from which the listener derives pleasure
The interpretation limiting kol isha to a woman's "sweet" or singing voice has been widely adopted,[14] overshadowing considerations of emotional connection.
Shulchan Aruch sets the stage for this approach in his ruling on kol isha during Keri'at Shema.
Shulchan Aruch OC 75:3
One must be careful not to hear a woman’s singing voice during Keri’at Shema.
A woman’s singing seems to present a halachic difficulty for a man reciting Shema, whether or not he finds it enjoyable. Note that Shulchan Aruch writes "one must be careful not to hear" rather than "one may not hear," which suggests that special care with kol isha in the context of keri'at Shema applies only le-chatchila, ab initio.[15]
Rema may be understood to extend the distinction between different types of voices beyond the context of keri'at Shema. First he writes that even the voice of a man's wife may be kol isha for him, presumably during keri'at Shema. Next, in a claim that seems more general, he draws on a statement of Rabbeinu Chananel[16] to characterize a "voice to which [a man] is accustomed" as a female voice that is not considered erva.
Rema to Shulchan Aruch OC 75:3
Even with his wife, but a voice to which he is accustomed is not erva.
This Rema may provide grounds for leniency with kol isha when a man has become accustomed to a given woman's voice, even in song, as with an immediate family member (a point we come back to in our next installment of this series).
Taking this logic further, one might claim that nowadays, with women's singing more common, we could consider men hearing women sing to be customary and generally permissible. Rav Ovadya Yosef, however, explicitly rejects this line of argument:
Yabia Omer I: OC 6
Don’t take it into your head to say that nowadays we are considered to be accustomed to women’s voices and there is no concern for inappropriate thoughts, similar to what Rabeinu Chananel wrote, that it is permissible for one who is accustomed to a voice (although there, he was referring to her ordinary voice, not to singing). We cannot say such things based on our own opinion so long as it is not explicit in the Talmud and halachic decisors.
Rema's reference to "the voice to which he is accustomed" may simply mean 'a speaking voice.' More fundamentally, Rav Yosef argues that we do not have the authority to argue that kol isha no longer applies.
A Different Approach
Recently, Rosh Yeshiva of Yeshivat Har Etzion Rav Mosheh Lichtenstein has suggested rethinking the singing-speaking distinction, based on Ra'avad's reasoning. He suggests that whether a voice entails kiruv da'at should be the essential litmus test for whether it is kol isha, regardless of whether a woman sings or speaks:[17]
Rav Mosheh Lichtenstein, Kol Isha: A Woman's Voice, Tradition Spring 2013, 46:1
Therefore, we should no longer distinguish between women’s singing and speech. Rather, we should limit the prohibition of kol isha to specific contexts only. Were there a specific prohibition of women’s singing, there would be room to argue that the prohibition is absolute. As it turns out, since the prohibition is not limited to song, but rather includes speech as well, we must necessarily limit it to specific contexts … From here we conclude: song which leads to feelings of intimacy between a man and a woman, or which emphasizes the singer’s sensuality and femininity for the listener, or if it sexually stimulates him – is forbidden to be listened to. However, song which does not lead to feelings of intimacy or sexual thoughts is not forbidden.
Rav Mosheh Lichtenstein thus has called for applying kol isha only to song that fosters kiruv ha-da'at or otherwise "emphasizes the singer's sensuality and femininity," which raises more considerations of tzeniut.
In a communication to a community rabbi that he shared with us, Rav Mosheh notes that the second factor might apply in the case of female soloists even when there is no clear kiruv ha-da'at, though specific applications would depend on context.
Israeli performer Avital Macales provides some insight into how the potential for intimacy has affected her personal decisions about where to perform:[18]
Avital Macales, interviewed by Varda Epstein, "Count the Stars." Jerusalem Post, 11 November, 2014.
In recent years, I began to better understand the complexity of [Kol Isha], and I challenged myself more about whether or not I wanted to get out there and perform in front of mixed audiences….After much thought I came to the decision that I’m still going to sing only in front of women and my personal reason is… There’s a certain intimacy that I want to bring to the stage. I want to be completely intimate with my audience, and I don’t want anything to block that. I just want to be completely open, and I feel completely open in front of an all-women’s audience.
Rav Mosheh's arguments notwithstanding, the predominant halachic approach to kol isha still applies it to singing in general, with or without kiruv ha-da'at.
In our next installment, we take a closer look at to whose voice kol isha applies, at what this discussion means for women and at alternative possible ways to contextualize kol isha.
Further Reading
Rav Chaim Jachter, "The Parameters of Kol Isha." Kol Torah. https://www.koltorah.org/halachah/the-parameters-of-kol-isha-by-rabbi-chaim-jachter
Rav Mosheh Lichtenstein, "Kol Isha: A Woman's Voice." Tradition Spring 2013 Issue 46.1 https://traditiononline.org/kol-isha-a-womens-voice/

[1]  Moses Maimonides, The Guide of the Perplexed, trans. Shlomo Pines (Chicago: University of Chicago Press, 1963), 435.
Rosh Ketubot 7:11
Dat Yehudit causes forfeit [of the ketuba] because of brazenness and because of the suspicion of adultery
[3] The same passage defines typically-covered parts of a woman’s body as erva:
Berachot 24a
Rabbi Yitzchak said: An [exposed] handsbreath of a woman is [considered as akin to] nakedness [erva]. For what [halachic context]?…[Even] with his wife and for reciting Shema. Rav Chisda said: A woman’s thigh is erva, as it is said, “Reveal your thigh and cross rivers” (Yeshayahu 47:2) and then is said, “Expose your erva and your shame will also be seen” (Yeshayahu 47:3).Rav Sheshet said: A woman’s hair is [considered as akin to] nakedness [erva], as it is said, “Your hair is like a flock of goats” (Shir Ha-shirim 4:1)
For more on this topic, see our discussions in Dress I and Dress III.
[4] ibid
[5] A parallel passage, from the Talmud Yerushalmi, bases itself on a homiletic reading of a verse in Yirmiyahu:
Yerushalmi Challa 2:1
Shemuel said: a woman’s voice is erva. What is the reason? "And it will be from the ease [mi-kol] of her promiscuity that the Land is defiled" etc. (Yirmiyahu 3:9)
The Talmud reads the word "mi-kol" as referring to voice (kol) rather than ease and "her" referring to a woman as opposed to the Land. Thus, the verse describes "the voice of her [a woman's] promiscuity," similarly to the description of Yael's voice above (Bavli Megilla 15a), and thus grants the woman's voice erva status.
[6] Ra'avyah explains that the verse in Shir Ha-shirim establishes a woman’s voice as a potential erotic distraction to men reciting Shema, even though it can't be seen.
Ra’avyah I, Berachot 76
I say the reason is that, even though the voice cannot be seen, there are nevertheless inappropriate thoughts…
Yere'im 392
Shemuel said: A woman’s voice is erva, as it is written, For your voice is sweet, meaning, the singing voice. And all these, Rav Yehudai Gaon explained as being for the matter of Keri’at Shema. Therefore, it is prohibited to recite Keri’at Shema or sacred words while hearing a woman’s voice singing.
Sedei Chemed, Ma’arechet Ha-kof 42
In my humble opinion, were it not for the words of Rashba in his novellae to Tractate Berachot, where he demonstrated from the above Talmudic discussion that [a woman’s] speaking voice is also prohibited, it would be possible to say that it is exceptionally pious conduct and he meant that, since Shemuel said that a woman’s voice is erva for every person with her singing voice, I am stringent even with her speaking voice, since it is fitting for an important person to be stringent, and thus I saw according to the Rav [author of] Chut Ha-meshulash.
[9] Some have taken this to mean that kol isha is specifically not a problem during Keri'at Shema, and only at other times. This view is hard to reconcile with the rest of the Talmudic passage, which treats Keri'at Shema as a time at which we are more particular about erva.
Shulchan Aruch EH 21:1
…And it is prohibited to hear the voice of an erva or to see her hair.
[11] Compare with Ohel Mo'ed, a few generations later, also from Catalonia:
Ohel Mo’ed, Sha’ar Keriat Shema, Derech 5
A woman’s voice, if it is greetings of peace, it is prohibited…the singing voice even with his wife is erva.
Ra’aviyah I: Berachot 76
Everything [we mentioned above] regarding erva applies specifically to something that they are not accustomed to uncover, but a maiden who is accustomed to go with her hair uncovered is not cause for concern, for there are no improper thoughts, and similarly with her voice [for one who is accustomed to it].
[13] The view that kol isha applies to the voices of unmarried women in niddah is widely held today, though it is less explicit in earlier halachic works.
Mishna Berura 75
The singing of a married woman, and similarly all forbidden women (arayot), is always prohibited to hear, and similarly an unmarried woman who is nidda, since she is included among the arayot, and our maidens are all presumed to be niddot from menarche.
Beit Shemuel EH 21:4
The voice of an erva – but the voice of a single woman or the voice of his wife is permissible
Beit Shemuel EH 21:4
Specifically the voice of a [woman who is] erva [to him] is prohibited, but her speaking voice is permitted
Beit Yosef, OC 75
Rearding halacha it seems that we take the view of Rambam, and nevertheless it is good to be cautious ab initio…from hearing the voice of song of a woman at the time or keri'at Shema.
Kaf Ha-chayyim 75:25
“One must be careful not to hear a woman’s singing voice…” that is, le-chatchila
Hagahot Maimoniot, Laws of Keri’at Shema, 3:16
Rabbeinu Chananel explained…But a maiden who normally uncovers her hair, we have no concern, for there are no inappropriate thoughts, and similarly for a voice that he is accustomed to.
Rav David Bigman has made a parallel argument, that any song sung by a woman in an innocent framework with innocent intent is not considered kol isha.
Rav David Bigman, To what case does “kol be-isha erva” apply?
To summarize: One can be lenient with hearing a woman’s singing voice when the situation can be clearly assessed as innocent listening to innocent singing. This assessment depends on five conditions: context, appropriate atmosphere, the words of the song, the musical genre, and the dress and body language.
We have seen, though, that singing songs with other-than-innocent intent in an inappropriate atmosphere is prohibited for all Jews, not only for women.
The article is available here: http://www.maalegilboa.org/article/0