The 5th and final chapter of the tractate The music and joy of the simchat beit hashoevah - beginning with the flute, and carrying on for 5 or 6 days of Sukkot. The mishnah explains why 5 or 6 days in particular. The Gemara digs into the wording of the mishnah, and what the simchat beit hashoevah should be called. Which leads to a distinction between when the flute-playing for the simchat beit hashoevah would cancel Shabbat or not. Once the instrumental and the singing come together, that may be more than music, and become worship. Also, on the essence of song and the need for instrumental accompaniment - leading to whether the possible can be derived from the impossible. Unexpectedly, Moshe's flute had to be made of wood. Which conclusion draws on specific Gemara rules of interpretation.