"Johnny One Note" is a 1937 show tune from the 1937 Rodgers and Hart musical Babes in Arms,[1] where it was introduced by Wynn Murray.
Judy Garland sang it in the Rodgers & Hart biopic Words and Music (1948).
[2] Popular recordings in 1937 were by Hal Kemp & His Orchestra (vocal by Skinnay Ennis) and by Victor Young and His Orchestra (vocal by Bobby Dolan).
[3]