The term jam band is commonly used to describe psychedelic rock-influenced bands whose concerts largely consist of bands reinterpreting their songs as springboards into extended improvisational pieces of music. The term less describes a set genre of music than it does provide a label for vastly different bands for whom the only link to each other is this improvisation.

While the Grateful Dead are generally accepted to be the founders of the jam band scene, the concept of spontaneous improvisation of music is by no means their invention. Early jazz musicians both pioneered the idea of improvisation and coined the term 'jam', though these 'jam sessions' tended to be completely free of constraints, whereas bands in the jam-scene tend to use the pretense of being confined by the boundaries of the song they are 'jamming out'.

Contents

1 Types of jamming 1.1 Type I 1.2 Type II 1.3 Segues 2 Types of jam bands

Types of jamming

A Phish fan named John Flynn once noted that the band had two distinct styles of improvisation. Expanding those two defined categories, these can be applied to the music of jambands as a whole.

Type I

Improvisations based around the already existing chord progressions of pre-composed songs, consisting of variations on the written notes and tempo. This is arguably a logical progression of the guitar solo, a feature of traditional rock music.

Type II

Jams which completely improvise the notes, tempo and structure of the music. Though these can and often do involve long workouts which end up sounding nothing like the songs they started out as, they are differentiated from jazz jams in that they mostly begin as a Type I jam.

See also: free improvisation

Segues

Segues can take the form of either Type I or II jams, but are slightly different in that either their original aim or the coincidental result of the jam is to act as a segue into another song.

Types of jam bands

With few exceptions, the jam-scene pre-1990 was primarily the scene of the Grateful Dead. Beginning with the formation of Phish in the mid 1980s, the jam band scene gradually gained momentum.

Musically, this new breed of bands contrasted heavily with the traditional camp by means of song structure. Spurred on by the pop success of Dave Matthews Band and often heavily influenced by modern-rock bands such as Pearl Jam and Hootie and the Blowfish, bands such as Spin Doctors, G. Love & Special Sauce, The Samples and Agents of Good Roots began playing jammed out acoustic pop, paying more attention to lyrics and seemingly aiming for commercial success. With few exceptions, the improvisation in their live shows tended to stick to Type I jams and segues, treating their songs as songs, rather than launchpads for lengthly improvisational workouts favoured by their peers.

See also: List of jam bands