5 minutes for a Kyrie? Sheesh! All in proper proportion. It’s the “music in the Mass” not “the Mass in the music.”
While I am a HUGE devotee of polyphonic pieces, there are some out there that are just totally inappropriate for the Holy Sacrifice of the Mass. It should move (like Gregorian chant) and not become so lengthy that it draws too much attention to itself.
Lest someone accuse me of being a trendy lib, I want to make sure people understand: I started a men’s Gregorian chant group in our town, and we are enjoying our 6th year. We sing chant, polyphony, and try to include Latin in as many parts of the Ordinary of the Mass and Divine Office whenever we visit parishes for liturgical events.
But to spend 5 minutes on an Ordinary part of the Mass that, were it chanted, would only last 45 seconds tops, is a* concert*.