Born in Budapest, Austria-Hungary (now Hungary). Composer and songwriter, educated at the University of Budapest and the Academy of Music in Budapest. He wrote several operettas in Europe and the USA, including "The Black Pierrot", "The Red Cat", "Natja", "White Lilacs", and "America Sings". Joining ASCAP in 1929, his popular-song compositions include "Falling Leaves", "Beautiful Dawn", and "Melodies Within My Heart". Hajos was with Paramount Pictures for a number of years before turning to free-lancing, composing music (usually uncredited) for over 90 films.

Nominated for Music Scoring Awards (Scoring of a Dramatic or Comedy Picture) 1944: SUMMER STORM  Nominated for Music Scoring Awards (Scoring of a Dramatic or Comedy Picture) 1945: THE MAN WHO WALKED ALONE 2 nominations