We do not [blow] less than twenty-one trumpet blasts in the Temple, nor more than forty-eight. We do not [use] less than two lyres, nor more than six. We do not [use] less than two flutes, nor more than twelve. On twelve days during the year, the flute plays before the Altar: During the slaughtering of the first pesach offering, and during the slaughtering of the second pesach offering, and on the first Yom Tov of Pesach, and on the Yom Tov of Shavuos, and on the eight days of the Festival. And he would not play a copper flute, but a reed flute, because its sound is pleasant. And he would conclude with only a single flute, because it would make for a better close.

They were the slaves of the Kohanim; [these are] the words of R’ Meir. R’ Yose says: They were the families of Beis Hapegarim and Beis Tzipporiah, and from Emmaum, from which Kohanim would marry. R’ Chananya ben Antignos says: They were Levites.