In 1974, Producer Stephen J. Cannell gave composer Mike Post his first opportunity to write a TV theme song, for “The Rockford Files.”  While Post went on to become one of Hollywood’s top composers — his TV themes include “Hill Street Blues,” “Quantum Leap,” and “NYPD Blue” — he was always happy to help when Cannell needed a new theme, which resulted in memorable themes for “The A-Team” and “The Greatest American Hero.”  Cannell told us about the pair’s working relationship over the years.  (CLICK BELOW TO HEAR STEPHEN J. CANNELL)