Thomas Merton explains why Gregorian chant rules:
"The cold stones of the Abbey church ring with a chant that glows with living flame, with clean, profound desire. It is an austere warmth, the warmth of Gregorian chant. It is deep beyond ordinary emotion, and that is one reason why you never get tired of it. It never wears you out by making a lot of cheap demands on your sensibilities. Instead of drawing you out into the open field of feelings where your enemies, the devil and your own imagination and the inherent vulgarity of your own corrupted nature, can get at you with their blades and cut you to pieces, it draws you within, where you are lulled in peace and recollection and where you find God."
In short: chant will still be sung a thousand years from now, while all the vapid "praise songs" and Christian pop music that stultifies so much contemporary worship are long forgotten.
Fr. Merton may have gone a little overboard with the fashionable leftism that washed into the Church in the 60's, but he remains one of the most skilled Catholic writers of the 20th century, and his conversion, described in his autobiography The Seven Storey Mountain, is one of the most influential of a century that drew many great men and women of letters into, or back to, the Church.
In 1867, Matthew Arnold wrote "Dover Beach", a haunting poem evoking the "melancholy, long, withdrawing roar" of the Sea of Faith. As a boomer who finished Catholic elementary school in 1964 and then watched my Church falter, I've found the roar all too audible. So here I wait, listening for the whispers of that Sea's invincible return.
