Written and first recorded (as “Leavin’ It All Up to You”) by Don & Dewey (1957).
Hit versions by Dale & Grace (US #1/R&B #6 1963), Donny & Marie (US #4/C&W #17/UK #2 1974).
Also recorded by Linda Ronstadt (1970).
From the wiki: “‘I’m Leaving It All Up to You’ was written and first recorded by the Rock ‘n’ roll and Doo-wop duo Don & Dewey in 1957. Don & Dewey were Don ‘Sugarcane’ Harris and Dewey Terry, both of Pasadena, California. Both Don and Dewey played guitar, with Dewey often doubling on keyboards. When not playing guitar or bass, Don occasionally played the electric violin, a skill for which he subsequently became well known under the name of ”Sugarcane’ Harris’. ‘Wrecking Crew’ drummer Earl Palmer played frequently on their sessions.
“In 1970, Harris re-emerged from semi-retirement to a wider rock audience, playing violin on the Hot Rats solo album by Frank Zappa, with Captain Beefheart (vocals) on ‘Willie The Pimp’ and on the lengthy instrumental jam, ‘The Gumbo Variations’. Harris went on to play on many more solo Zappa, and Mothers of Invention, albums.