The spinoff character Savage Henry, guitarist for the Bugtown band the Bulldaggers, ended up with his own series, published from 1987-1994.
The real-world experimental musician Conrad Schnitzler of (Tangerine Dream and Kluster) was a regular guest in Those Annoying Post Bros., appearing in issues #2, 5, 42, 48, 50, and 63 (with cameos in issues #7, 16, and 41); and Annuals #1-2 (with a cameo In #3).