Hoagy Carmichael's “Skylark,” published in 1941, was originally written for a musical about his deceased friend, trumpeter Bix Beiderbecke, and was said to have been based on Beiderbecke solos. Carmichael later reworked the composition and passed the melody on to Johnny Mercer for lyrics--but by the time Mercer called months later to sing the completed lyric, Carmichael had completely forgotten that'd he'd written it.