Eberly was hired by the Dorsey Brothers Orchestra in 1935 shortly after winning an amateur hour contest on Fred Allen's radio show and shortly before Tommy Dorsey left the band to form his own group. Eberly stayed with Jimmy Dorsey and would be a fixture with the orchestra until drafted into the service late in 1943. In the early 1940s the Jimmy Dorsey Orchestra scored a string of hits featuring Eberly and Helen O'Connell, with Eberly singing a slow, romantic baritone version of songs such as Amapola and Tangerine, followed by a lighter, up-tempo reprise by O'Connell. Eberly also recorded the original version of "I'm Glad There Is You" in 1942 for Dorsey's orchestra on Decca Records. The song has become a jazz and pop standard.