Bunny Sigler is an unsung hero of Philly soul.
In the '70s he wrote songs for the O'Jays ("Sunshine," "Now That We Found Love") and other artists at Philadelphia International Records while contributing backing vocals and guitar in the studio. He also recorded his own songs for the label, including a gospel-ish version of the O'Jays' "Love Train" that cracked the top 30 of Billboard's R&B chart in 1974. He also knows karate, which in my opinion is preferable to knowing "ka-razy."
You can read more about Sigler and the 1996 compilation The Best of Bunny Sigler: Sweeter Than the Berry over at Jefitoblog.