>>My point was that the Church from old times has recognized the need for some variation in the music<<
No, they have allowed for variation.
But if one is speaking of pre-Vatican II the chant never changed in a low mass nor in a High Holy Mass. The Church recognized that Catholics thrive on repetition. Parish to Parish one heard the same music and same chant.
Vatican II allowed change in the liturgy. With it came the “Kumbaya Catholics” who thought everything should be changed to make it better when nothing was actually broken.
If we want to bring Catholics back to the Church, give them Old Time Catholic Masses. Push for one in every parish. Because I can tell you, in my area, my parish (where we kneel for communion), Assumption Grotto (who’s altar faces east) and San Francisco (that chants every mass) are packed and the other parishes with the great performers are closing and clustering.
But we don't want to repeat the mistakes that were made around the time of VCII, and rush in a bunch of unfamiliar stuff on people. Just because the orthodox were bewildered, offended and annoyed when the wreckovationists ripped out the kneelers overnight and made everybody change without any warning or preparation, doesn't mean we should do it back (as appealing as that is to a sense of cosmic justice).
So we phase out the awful hymns, phase in the good ones, add more and more Latin to the Mass where we chant the Ordinary (with the wholehearted cooperation of our Parochial Vicar, who is learning the Extraordinary Form), and try to keep the congregation up to speed on the changes without overtaxing them.
It's a delicate process. But we hear through the ecclesiastical grapevine that we are attracting folks from all over, so even if we're proceeding slowly it's having a good effect. Link by link is chainmail made, as one of Kipling's characters said, or "brick by brick", quoth Father Z.