- Apr 1 Douglas Allenbrook, composer
- Apr 1 William L Bergsma, American composer (Fortunate Island), born in Oakland, California
- Apr 6 Andrew Welsh Imbrie, composer
- Apr 8 Jan Novák, Czech classical composer, born in Nová Říše, Morovia (d. 1984)
- Apr 10 Sheb Wooley, American vocalist (Purple People Eater, Hee Haw), born in Erick, Oklahoma (d. 2003)
- Apr 19 Will Ogdon, American composer, born in Redlands, California (d. 2013)
- Apr 22 Cándido Camero, Cuban American percussionist (congo drum) and bandleader, born in Havana, Cuba (d. 2020) [1]
- Apr 23 Janet Blair [Martha Janet Lafferty], American singer and actress (Leave it to the Girls, Smith Family), born in Altoona, Pennsylvania (d. 2007)
- Apr 24 Laci Boldemann, Swedish composer, born in Helsinki, Finland (d. 1969)
- Apr 26 James "Jimmy" Giuffre, American jazz musician, composer, and arranger, born in Dallas, Texas (d. 2008)
About April 1921
How Old? 99 years old
Generation: Greatest Generation
Leap Year: No