The teeth are a good place to start when trying to identify this classic rocker in his youth. Not that the singer has bad teeth now -- they weren't even awful then -- but his smile today pretty much matches the one he flashed 45 or 50 years ago. He was a key part of one of the most successful bands of the late '70s and early '80s, but he wasn't the original singer. Do you think you know who it is? 

This man calls Chicago home and graduated from Brother Rice High School in the late '60s. He was barely 21 when he recorded his first album with the band in the early '70s. Internal conflicts forced him out of the group, but he was invited back in 1976 for a run that's still continuing. The band still makes records, and fans keep on loving them (wink, wink) at live shows, although only one original member of the group remains.

Click the button below to find out if your guess is right, and to find out what sweet rock act he was able to book for his senior prom at Brother Rice.