I'm a BT and have gotten my bachelor's and master's in percussion performance. I started becoming observant during my master's and now I'm wondering how the future will be playing music and being a Torah-observant Jew. I know there are even questions about playing music at all, especially for not simchas, but what is the halacha about a woman playing an instrument in front of a man? Is this assur? Is it not tznius? Thank you in advance.
C-5. Women Doing Jobs That Attract Male Spectators: A man may hear music produced with musical instruments by a woman or a group of women. Since no female voice is involved, the issur of קול באשה ערוה does not apply (Aruch HaShulchan 75:8).
This also follows the view found in Halichos Bas Yisroel, vol. 1, pg.99, chap. 6:13
However, according to Rabbi Falk, there is a prohibition on the man to watch a woman play a musical instrument.
It is, however, ossur for men to observe women playing musical instruments because there is a general issur for women to exercise special skills in front of men as they thereby attract attention to their movements - see Teshuvas HaRadvaz 2:770 and Responsa Mishnah Halachos 6:25.
He bases this upon two sources. First, a responsum of Radvaz, (vol. 2, letter 770), which discusses the prohibition of a man walking behind a woman and explains that the reason for the prohibition is that seeing the woman's motion could lead to improper thoughts by the man.
Second, on the responsum of Rabbi Menashe Klein, the Ungvar Rebbe, who says there are two reasons for this prohibition. The first being based upon Shulchan Aruch, Orach Chaim 560:3 which discusses the restrictions associated with remembering that the Temple in Jerusalem remains destroyed. And the second reason is that brought from the Radvaz above.
According to the Radvaz, the prohibition he discussed is not dependent upon whether the women are dressed modestly or not and is applicable in all places. It is only related to whether men are able to see and discern the actual movement of the women.
So, if some mechitza arrangement were made, it would not be a problem.
קול באשה ערוה שנא' (שיר השירים ב, יד) כי קולך ערב ומראך נאוה
A woman’s [singing] voice is considered nakedness, [which he derives from the praise accorded a woman’s voice,] as it is stated: “Sweet is your voice and your countenance is alluring” (Song of Songs 2:14).
(Translation and elucidation from the William Davidson Talmud)
The Aruch Hashulchan concludes the discussion of this prohibition by saying that it does not apply to instrumental music:
ונראה דדוקא כשמשוררות בפיהן הוה איסור, ולא כשמנגנות על הכלי, דבזה לא שייך הרהור וערוה.
And it seems that it's specifically when [women] are singing with their mouths that there's a prohibition, but not when they are playing music with an instrument, as there, improper thoughts and nakedness are not involved.
1. Or perhaps Talmud Yerushalmi, Challa 12b, which cites a different Biblical prooftext. (Hat-tip: DoubleAA)