Bob Moore, a bassist in Nashville’s “A-Team” of sessions musicians, has died at 88, according to Billboard. He played on countless songs over his decades in the business, including performing on the studio versions of Elvis Presley’s “Are You Lonesome Tonight?,” Patsy Cline’s “Crazy,” Loretta Lynn’s “Coal Miner’s Daughter,” Kenny Rogers’ “The Gambler,” Brenda Lee’s “Rockin’ Around The Christmas Tree,” and many others. In 2007, when he was celebrated at the Country Music Hall Of Fame in its Nashville Cats series, Moore estimated that he played on more than 17,000 songs.

Moore was born in Nashville in 1932. By the time he was 9, he was invited backstage at the Grand Ole Opry after drawing attention by setting up a shoeshine stand on the corner near the entrance. He started performing by age 10 and by 14 he was already on the road with the duo Jamup & Honey and later Paul Howard & His Arkansas Cotton Pickers.

By the ’50s, he started playing in recording studios around Nashville. He became one of Elvis Presley’s favorite session players and went on to work for Pasty Cline, Loretta Lynn, Brenda Lee, Bobby Darin, Connie Francis, and many others. That’s around the time that the Nashville “A-Team” solidified, which Moore was a part of. He helped establish Monument Records, which is where he released “Mexico,” an instrumental written by Boudleaux Bryant that became Moore’s only Billboard-charting single under his own name.

“Bob Moore’s contributions to American music are incalculable,” Country Music Hall Of Fame And Museum CEO Kyle Young said in a statement. “He was a musical master and the most-recorded bass player in country music history. As a key member of the much-vaunted ‘A-Team’ of Nashville session players, he was both an inspiration and an innovator. […] He once said, ‘Anyone who has heard me play the bass knows my soul.’ We’re fortunate that he shared his soul with us for so many years.”