If you like music, (and I'm guessing that if you're reading this - you have a passing interest in it,)  you might be familiar with Johann Sebastian Bach's  "Jesu, Joy of Man's Desiring."  If you're not, - listen to it here - takes about 2 minutes, you'll get the idea.

To me, it's one of those pieces that on hearing you instantly recognize - doesn't matter if it's a Rock Band playing , an Orchestra or a Beautiful Couple,  the piece is timeless, it is classic, it does indeed Rock!