Founding member of the rock band Chicago, the group that released "Saturday in the Park" and other hit singles. A singer and multi-instrumentalist, he played flugelhorn, drums, cornet, guitar, trumpet, and keyboard.
His band began as The Big Thing and was later re-named The Chicago Transit Authority before finally becoming Chicago.
He belonged to Phi Mu Alpha Sinfonia, a music fraternity.
He was married to Susan Marie Steele from 1970 to 1972. His 1979 marriage to Elizabeth Cunneff produced a son, and his later marriage to Patricia Leininger resulted in another two children. He later had another child with his fourth wife, Megan Cathleen Brown.
He and Peter Cetera helped found the band Chicago.