This mass was written by Giovanni Pierluigi da Palestrina around 1567.
Fitting to the epoch this mass is mostly polyphonic, nevertheless, one can find a few more classical sounding features in it as well. It is separated into the traditionally used parts of the mass: Kyrie, Gloria, Credo, Sanctus and Agnus Dei. A mixed choir is singing unaccompanied.
The first part “Kyrie” has a typical (even though not common for the time of the composition) A-B-A’ form. The only difference between the first and the second A-part, is, that the second one is louder than the first one. There are unison rests between every part. All in all, this part of the mass is relatively calm character, really slowly paced, but with warm harmonies. The Gloria is a very clear and bright sounding part. One can often notice loud echo-motives, which were rather unusual, due to the echoes being the loud part and the first phrases being quieter.
I’ve often noticed that the “Credo” is likely to be the longest part of a mass, as it is with this one. Here and also for the previous two parts the tenor voice makes the first entrance. This is the first part, which sounds a bit more dramatic and mysterious in certain ways. The voices nearly sing at the same time and therefore create an almost homophonic sounding character. The pace, dynamics and character stay roughly the same until the end of this part.
The “Sanctus” is the only part, where the tenors don’t make the first entrance. One even has the feeling as if the lower voices (Bass and Tenor) where accompanying the higher ones (Altos and Sopranos). This part too, has a slight dramatic character and Palestrina worked with strong contrasting dynamics as well. For the last part “Agnus Dei” the Tenor makes the entrance again. In the first half one can clearly mark some dissonances for the first time, which nonetheless fit well to the atmosphere of the piece. This is furthermore the only section which isn’t interrupted by unison rests.
I personally prefer it more when larger pieces of music, such as this one, are clearly structured, therefore I always find it a bit confusing listening to polyphonic pieces. It seemed to me as if Palestrina was always trying to reach a certain point with this piece of music, a climax to which he never quite gets too. The longer parts of this piece, in this case the “Credo” and “Sanctus” , where a bit calmer in terms of being more homophonic, but rather monotone after a short while.