He was an amazing studio musician before striking out on his own. Some of his work:
Hello Mary Lou by Ricky Nelson (1961)
Danke Schoen by Wayne Newton (1963)
Surf City by Jan and Dean (1963)
Whatd I Say by Elvis Presley (1963)
I Get Around by the Beach Boys (1964). Also “Dance, Dance, Dance and Fun, Fun, Fun and the groundbreaking LP Pet Sounds.
Youve Lost That Loving Feeling by the Righteous Brothers (1965)
Strangers in the Night by Frank Sinatra (1966)
Mary, Mary by the Monkees (1967)
Mama Tried by Merle Haggard (1968)
Turn Around Look at Me by the Vogues (1968)
Fun fact:
When he recorded "Wichita Lineman", Carol Kaye was in the studio & Glen borrowed her 6-string bass for the instrumental solo.