I don't know what denomination (if any) you belong to - but among Catholics attendance at Mass has declined more than 40% since "staid and traditional" liturgies were abandoned.
The most vibrant and fastest-growing Catholic communities in the US are the ones which have returned to dignified, solemn liturgy and the use of Latin.
If young people need contemporary music more than they need the Sacraments, they've already made their choice of which master they will serve.
Surely you don't expect me to believe that nothing changed from 33 AD until 1971? A few things like the printing press make that obviously untrue.
As I said before, someone else's "contemporary" became your "tradition." And your "contemporary" will become some future soul's "tradition." We need to keep things in perspective.
No, I'm not Catholic. But I am smart enough to realize how foolish it is to draw a direct correlation between the type of mass and attendance. There have been a "few" other things over the last few decades that also impacted attendance. Cause and effect is never that cut and dried.