Written and first recorded by Mac Davis (US #117/MOR #25 1971).
Other hit versions by Helen Reddy (AUS #2 1971), Gallery (US #22/MOR #12 1972).
Also recorded by Donny Hathaway (1971).
From the wiki: “‘I Believe in Music’ was written and first recorded, in 1971, by Mac Davis. His recording made a minor dent in the pop charts, ‘bubbling under’ the Billboard Hot 100 but peaking at #25 on the MOR song chart. Helen Reddy and Donny Hathaway also recorded versions of ‘I Believe in Music’ in 1971. Reddy’s recording peaked at #2 on the Australian music chart; Hathaway’s production was not released as a single but appeared on his 1971 self-titled album, Donny Hathaway.
“Gallery’s 1972 recording of ‘I Believe in Music’ was the second of three singles released from their Nice to Be with You album, peaking at #22 on the Billboard Hot 100.”