He is a keyboardist and singer-songwriter who was formerly with The Cowsills.
In 1992 he played the keyboards on Big Daddy’s cover of the Beatles album Sgt. Pepper’s and in 1996 he joined up with the The Beach Boys.
Here are the Beach Boys in 2007 performing “All Summer Long”…
Sources:
https://en.wikipedia.org/wiki/The_Beach_Boys_lineups
https://en.wikipedia.org/wiki/Sgt._Pepper%27s_(Big_Daddy_album)
https://www.discogs.com/artist/2528847-Tim-Bonhomme