Rabbi Alexandri bar Chagri [(and in Midrash Rabbah on Metzora, Parashah 19, and in Midrash Chazit, Parashah Rosh, it is mentioned that this matter pertains to Bar Chadrin)]. And Rabbi Alexandri, in connection with this, said, etc. [as it is known that he was a chazzan who recited piyyutim]:
Seder_HaDorot,_Tanaim_and_Amoraim.483:1