Shalom,
Whats the modern day equivalent of zimrei yevani visa vis Acher,please explain according to the different halachich authorities,I believe that there is teshuvah of R' M.Feinstein concerning types of music to which a ben torah may listen to.
Gut Shabbos.
Rav Moshe Feinstein in Yoreh De'ah (2:56) forbids singing and listening to songs composed for non-Jewish religious liturgy ("used in their houses of worship"). He adds that any music they composed based on verse from Tehilim was most likely composed for such purposes. It is therefore forbidden to sing or to listen to these songs even on a cassette (i.e. not live).
Rav Moshe brings as one source for this prohibition the Maharsha on our Sugay. Although Rashi explains that "Greek songs" (which casued Acher's fall) are forbidden in recognition of the Churban [as stated in Gitten 7a], the Maharsha asks many questions on this explanation. The Maharsha explains that Acher used to sing songs of Avodah Zarah. This shows us the extent and nature of this sin.
Aside from this prohibition, Rav Moshe discusses (OC 1:60:166) the prohibition of listening to music during a banquet or dinner (see Gittin 7a and Rashi there). Chazal also prohibit music when waking up or going to sleep (see Tosfos there - based on the Yerushalmi - and see also the Tur OC #560) because of the Churban. Excluding these times listening to music is permitted. This applies both to musical instruments and singing without instrumental accompaniment.
According to the Rambam (Ta'anis 5,14), though, the prohibtion of instrumental music applies at all times and all places. The Rambam holds that in banquet halls even singing without instrumental accompaniment is prohibited.
In one of his Teshuvos (quoted in the Tur cited above) the Rambam was even stricter, stating that even singing without instrucments is forbidden anywhere.
HALACHAH: The Shulchan Aruch (Orach Chaim 560,3) rules as the Rambam: Instrumental music is always forbidden, singing is forbidden in banquets and upon waking up and going to sleep. The Rema is more lenient, and rules that even instruments are prohibited only during banquets or upon waking and sleeping.
But Rav Moshe (ibid.) rules very stringently in this matter and concludes that the opinion of the Shulchan Aruch (the Rambam) is the majority opinion (not to listen to instruments ever). He adds that a "Ba'al Nefesh" should not even listen to singing without instruments anytime, as the Rambam rules in his Teshuvah.
For a Devar Mitzvah, though, music is permitted.
Mordecai