Dovid is the Leader of Singers:
The Medrash (Esther Rabbah, Pesichta 10:10) states: “’Who worked and did, Who calls the generations from the beginning... (Yeshaya 41:4).’ From the time of the creation of the world, Hashem has prepared for everyone to receive what they deserve. Odom was the ‘rosh’ (the first and the leader) of all creations. Kayin was the rosh of murderers. Hevel was the rosh of murder victims. Noach was the rosh of survivors. Avrohom was the rosh of the circumcised. Yitzchok was the rosh of ‘ne’ekadim’ (the sacrificed). Yaakov was the rosh of temimim (simple people). Yehuda was the rosh of the Shevatim. Yosef was the rosh of chasidim (righteous men). Aharon was the rosh of Kohanim. Moshe was the rosh of prophets. Yehoshua was the rosh of conquerors. Osniel was the rosh of dividers (of the land). Shmuel was the rosh of the anointers (of kings). Shaul was the rosh of the anointed (kings). Dovid was the rosh of musicians.
