Although virtually all jazz groups prior to the rise of bebop in the early to mid-'40s played for dancers, the term Dance Bands is used to describe orchestras of the 1920s and '30s whose primary function was to play background music for dancers rather than to serve as vehicles for jazz improvisations. The more progressive dance bands of the early to mid-'20s (such as those led by Paul Whiteman, Isham Jones, and Ben Selvin) left some room for short solos and by the late '20s most of the less commercial dance bands had brief spots in their arrangements for trumpeters or reed players to solo after the vocal refrain. The dance bands, although emphasizing the melody and vocalists, were generally influenced by jazz and incorporated elements of swing after the emergence of Benny Goodman in 1935, although they were often classified as "sweet" bands. After 1945, dance orchestras became less common, were often tied to nostalgia, and were much less relevant to jazz.