Jam sessions

A jam session is a relatively informal musical event, process, or activity where musicians, typically instrumentalists, play improvised solos and vamp on tunes, songs and chord progressions. To "jam" is to improvise music without extensive preparation or predefined arrangements, except for when the group is playing well-known jazz standards or covers of existing popular songs. Original jam sessions, also 'free flow sessions', are often used by musicians to develop new material (music) and find suitable arrangements. Both styles can be used simply as a social gathering and communal practice session. Jam sessions may be based upon existing songs or forms, may be loosely based on an agreed chord progression or chart suggested by one participant, or may be wholly improvisational. Jam sessions can range from very loose gatherings of amateurs to evenings where a jam session coordinator or host acts as a "gatekeeper" to ensure that only appropriate-level performers take the stage, to sophisticated improvised recording sessions by professionals which are intended to be broadcast live on radio or TV or edited and released to the public.

The phrase "jam session" came about in the 1920s when white and black musicians would congregate after their regular paying gigs, to play the jazz they could not play in the "Paul Whiteman" style bands they played in. When Bing Crosby would attend these sessions, the musicians would say he was "jammin' the beat", since he would clap on the one and the three. Thus these sessions became known as "jam sessions".

The New York scene during World War II was famous for its after-hours jam sessions. One of the most famous was the regular after-hours jam at Minton's Playhouse in New York City that ran in the 1940s and early 1950s. The jam sessions at Minton's were a fertile meeting place and proving ground for both established soloists like Ben Webster and Lester Young, and the younger jazz musicians who would soon become leading exponents of the bebop movement, including Thelonious Monk (Minton's house pianist), saxophone player Charlie Parker, and trumpeter Dizzy Gillespie. The Minton's jams had competitive "cutting contests", in which soloists would try to keep up with the house band and outdo each other in improvisational skill.

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