Coonce was born in Los Angeles, California on August 1, 1946, at The City Of Angels Hospital. He attended a Catholic school for six years while his mother worked to support the family. His father played the fiddle and his mother sang. Coonce developed an interest in music at an early age by observing his parents and his older brother’s guitar lessons, though his mother insisted he learn the accordion. He attended high school in Simi Valley and played in local bands in between working at a Sunkist Growers packing house.

In 1966, The Beethovens played at a Battle of the Bands in Hollywood and took second place. A future bandmate, Rob Grill was a singer in one of the other competing bands that night. They actually did better than The Beethovens but were disqualified because one of their band members was a professional musician, so Coonce’s group moved up in rank.

In 1967, the group changed their name to The Grass Roots to take advantage of prior name recognition and recorded “Let’s Live For Today”. The iconic song peaked at #8 on the Billboard Hot 100. Capturing the mood of the era, “Let’s Live For Today” kicked the group into stardom.

Coonce left the band in 1972 and moved to Vancouver, Canada, where he played in many local groups and recorded music in his home studio.