Free improvisation or free music is improvised music without any rules, and not in any particular style. Performers may choose to play in a certain style or key, or at a certain tempo, but it is not required. There is generally more emphasis placed on mood and texture than on melody, harmony or predictable rhythm.

Free music is a relatively little known, and somewhat loosely-defined genre, and none of its exponents can be said to be "famous" amongst the general public. However, in experimental circles, a number of free musicians are well known, including the guitarist Derek Bailey, and the saxophonistss Peter Brötzmann and Evan Parker.

Free music performers come from a variety of backgrounds, and there is often considerable influence on and from other musical genress. For example, much of self-taught Peter Brötzmann's output is also widely considered free jazz, and Tristan Honsinger studied at the prestigious Peabody Conservatory of Music. Elements of noise rock, IDM, minimalism and electroacoustic music are not uncommon in free improvisation.

Many free music performers also record and perform other styles of music: Anthony Braxton has written opera, and John Zorn has written acclaimed orchestral pieces.

Free music performers often emphasise extended technique.

List of free improvising musicians and groups (please add names in alphabetical order)

• AMM
• Derek Bailey- Guitar
• Anthony Braxton- Saxophone
• Han Bennink- Percussion
• Steve Beresford
• Birdyak (Bob Cobbing and Hugh Metcalfe duo)
• Borbetomagus
• Ian Brighton- Guitar
• The Brotherhood of Breath
• John Butcher
• Company
• Lol Coxhill- Saxophone
• Guenther Christmann-Trombone, Cello
• Terry Day- Percussion
• Johnny Dyani- Double bass
• The Feminist Improvising Group
• G F Fitzgerald- Guitar
• Fred Frith- Guitar
• Patrick Frye III- Harpsichord, Piano and Synthesizer
• Barry Guy- Double bass
• Tristan Honsinger- Cello
• Iskra 1903
• Peter Kowald- double bass
• Steve Lacy- Saxophone
• Paul Lovens- Drums
• Paul Lytton- Drums
• Misha Mengelberg- Piano, toys
• Phil Minton- Voice
• Louis Moholo- Drums
• Butch Morris- cornet and conductor
• nmperign- Duo of soprano saxophonist Bhob Rainey and trumpeter Greg Kelley
• Tony Oxley- Percussion
• Maggie Nicols- Voice
• Evan Parker- Saxophone
• Frank Perry- Percussion
• poire_z
• Radar Favourites
• Red Balune
• Hans Reichel- Guitar
• Keith Rowe- Guitar
• The Sisterhood of Spit
• Roger Smith- Guitar
• Spontaneous Music Ensemble
• John Stevens- Percussion and trumpet
• Keith Tippett- Piano
• Voice Crack
• Philipp Wachsmann- Violin
• Kenny Wheeler- Trumpet
• John Zorn- Saxophone

See also: free jazz, Musics magazine, Incus Records, Improvised Music from Japan, List of experimental musicians