RIP indeed ... prior to his solo career he was with "The Wrecking Crew" ..
https://en.wikipedia.org/wiki/The_Wrecking_Crew_(music)
They were the band in the 60's ... they played the music for more songs that you would ever guess ...
Pet Sounds was the Beach Boys right? Nope!!
Look up their biography on Netflix! (Muscle Shoals too!)
Glen had more of an influence on music than you might have thought ...
Again , RIP Glen