Final answer:
The Gloria from Palestrina's Pope Marcellus Mass is characterized by full and consonant harmony, reflecting the polyphonic texture of the Renaissance period in music.
Step-by-step explanation:
The harmony of the Gloria from Palestrina's Pope Marcellus Mass is indeed best described as full and consonant. This work is renowned for its polyphonic texture, which was a hallmark of the Renaissance period in music. The mass achieves a beautiful blend and balance between the vocal lines, which are woven together to create harmony that was considered ideal during this era. Palestrina's music, especially in the Pope Marcellus Mass, emphasizes a smooth, flowing melody and a clear harmonic structure that avoids the dissonances typical of the Medieval period.