My point was that the Church from old times has recognized the need for some variation in the music (as opposed to the text, which does not change). That's because the folks compiling the Liber were musicians and understood what music and musicians require in order to do their best.
We do have three Mass settings - one for the Latin Mass and two for the Ordinary Form. The congregation doesn't seem to mind (although they are struggling with the Latin).
>>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.