what instruments or voice have the Pope Marcellus Mass Gloria melody through the song?

In the "Gloria" from Palestrina's Pope Marcellus Mass, the melody is primarily sung by the choir, showcasing a rich polyphonic texture. The piece features a four-part vocal arrangement, typically performed by soprano, alto, tenor, and bass voices. While the original composition is a cappella, it can also be accompanied by instruments such as organ or strings in modern performances to enhance its harmonic depth.