No untold story here . . .
George was a well-known arranger in Hollywood.
Jan was introduced to George when Jan came up with the idea for "Pop Symphony." They hit it off, and collaborated on that project.
Jan and George became friends, and worked a lot together. After "Pop Symphony," George collaborated with Jan as an arranger on Folk 'n Roll and Jan & Dean Meet Batman. George did some writing, as well.
George was also an arranger with Jan on the original Filet of Soul. In the '66 TV pilot, On the Run, that's George you see conducting the orchestra -- and he also did the incidental music for the show.
After Jan's accident, George (along with Bill Stafford) was Jan's main arranging collaborator on Carnival of Sound.
I've interviewed George. One of the greats from the Hollywood studio system.