I don't know if he is there, but it's a very good possibility because the band for the stand up shows & the set pieces are basically Spector's Wrecking Crew.
Tommy Tedesco guitar,
Al Casey guitar,
Larry Knechtal keys,
Don Randi keys,
Hal Blaine drums, John Cyr percussion,
Frank DeVito percussion,
Tommy Morgan harmonica.
They are also the same crew that played on most of the Beach Boys'albums, including Pet Sounds, the Byrds' Mr. Tambourine Man, as well as many other classic 60's songs. It's quite likely he'd go along with them just to watch.