A jazz ensemble usually plays music without a conductor and Jazz bands usually consist of a rhythm section and a horn section. The instruments typically include soloing instruments (one or more saxophones, trumpets, etc.) one or two chordal instruments (electric guitar, piano, or organ), a bass instrument (electric bass guitar or double bass), and a drummer or percussionist.
Small jazz combos play light dinner jazz.
Big jazz bands (playing the classic jazz music of Cole Porter, George Gershwin, Glenn Miller) are for dancing after dinner.
Swing jazz bands will play a wide array of jazz music ranging from a sophisticated big jazz band sound to the more modern swing jazz bands such as The Brian Setzer Orchestra and Harry Connick Jr.
Latin jazz music has become quite popular as well, and many jazz bands have Latin jazz in their repertoires.