I don't know about all of you but,I think classical music is the ultimate test for any vintage JBL. We all know what really made JBL famous "The L100's" and we know what made the L100's famous "Rock Music" In the 70's Rock never sounded so good than it did on the L100's. The true beauty and appreciation of vintage JBL'S comes from Classical music. To listen to all those symbal's, horns,trumpet's and drums is just breathtaking, I loved JBL for the way it made rock music sound when I was a teenager in the 70's"hell who don't like rock? I never tested JBL'S with rock music if I was going to buy a pair, I always used classical music. My favorite piece to check JBL'S ,is the theme from "How The West Was Won", you must hear this on some old JBL'S.Another piece is the main theme from the movie"Rudy" and the main theme from "Lonesome Dove". What is your favorite piece of classical music to play on your JBL'S? I haven't given up Rock music but now I am in my 50's more relaxed and can't take the volume like I used to.What ever you enjoy,enjoy it with JBL!