Our Sages teach us (Bava Basra 14b) that King David wrote the Psalms (T’hilim) based on his own experiences, along with the contributions of other great Jewish figures. While the Book of T’hilim was composed mainly by King David, the Gemara (Bava Basra 14b) enumerates ten authors who composed psalms other than King David. The Gemara speaks of these men as “Asarah Z’keinim,” ten Elders, great scholars endowed with profound wisdom and prophetic insight, which enabled them to compose such a sacred text. Psalm 139 was attributed to Adam HaRishon. Another psalm was composed by King Malki-Tzedek. Psalm 89 is attributed to Avraham Avinu. There are 11 hymns composed by Moshe Rabbeinu. There are several chants composed by the Leviim who officiated as singers in the Beis HaMikdash.