- Oct 1 Héctor Campos Parsi, Puerto Rican classical music composer, born in Ponce, Puerto Rico (d. 1997)
- Oct 13 Harper MacKay, American orchestra leader (NBC Follies), born in Boston, Massachusetts (d. 1995)
- Oct 21 Jarmil Burghauser, composer
- Oct 21 Sir Malcolm Arnold, British trumpeter, and classical and film score composer (The Bridge On The River Kwai), born in Northampton, England (d. 2006)
- Oct 23 Denise Duval, French soprano, born in Paris (d. 2016)
- Oct 27 Anestis Logothetis, Austrian composer, born in Burgas, Bulgaria (d. 1994)
About October 1921
How Old? 99 years old
Generation: Greatest Generation
Leap Year: No