Bruce Arnold is an American jazz guitarist, composer and educator who has built two parallel careers out of the same set of ideas: a thirty-year recording catalog that applies twentieth-century classical theory to jazz improvisation, and a publishing operation, Muse-eek Publishing, that has made him one of the most widely read guitar-method authors working. Born in Sioux Falls, South Dakota, on July 31, 1955, he started on accordion and switched to guitar after seeing the Beatles on The Ed Sullivan Show. He spent two years at the University of South Dakota before transferring to the Berklee College of Music in 1976, arriving in a guitar department whose students at the time included Mike Stern, Bill Frisell, Steve Vai, Wayne Krantz, John Scofield and Kevin Eubanks. Away from the school he studied privately with two Boston teachers he has repeatedly named as the decisive influences on his direction, the pianist and ear-training pedagogue Charlie Banacos and the saxophonist Jerry Bergonzi.

Arnold stayed in Boston through the mid-1980s, joining the Berklee faculty in 1984 and working as a guitarist across the city's session and jazz scenes. His earliest documented recordings date from that year: the vibraphonist Ed Saindon's Different Strokes, the vibraphonist Víctor Mendoza's self-titled debut, and Le Quartet Bash's album for Bashful Records, on which he is credited on both guitar and banjo. In 1989 he appeared on drummer George Schuller's Lookin' Up From Down Below for GM Recordings, a date whose front line was Joe Lovano, Tiger Okoshi and Gary Valente over bassist Ed Schuller; Arnold plays on five of its tracks.

He moved to New York City in 1988 and began teaching at New York University the following year, adding Princeton in 1990, where he ran the guitar program until his retirement from the post in 2019. He has also taught at the New England Conservatory, Dartmouth College, the New School and the City College of New York, and he serves on the jazz advisory committee of Local 802 of the American Federation of Musicians. It was at NYU that he created the Summer Guitar Intensive, an annual gathering of visiting guitarists that has generated several of his own recordings and at least one commercial video release. Away from the classroom his performing credits from these years include work with Joe Pass, Peter Erskine, Randy Brecker, Stanley Clarke, Roswell Rudd, Stuart Hamm, Lenny Pickett, the Boston Symphony Orchestra and the Absolute Ensemble under Kristjan Järvi, and he has toured in Australia, Canada, the Caribbean, Europe, Japan, Mexico and Russia.

His recording career as a leader opens in 1995 with Act of Finding on OODiscs, a collective quartet with baritone vocalist Thomas Buckner, electronic composer Tom Hamilton and bassist Ratzo B. Harris, and continues the following year with Blue Eleven, his first widely distributed leader date. The spine of the catalog through the 2000s is a working trio with Harris on bass and Tony Moreno on drums, documented across A Few Dozen (2000), Give 'Em Some (2002), Blue Lotus (2007) and Multiplicity (2010); by the time of Blue Lotus the three had been playing together for fifteen years. That trio is where his central preoccupation is easiest to hear, an attempt to build swinging, improvised music on pitch class set theory rather than on functional harmony. He also became one of very few electric guitarists to use the audio programming language SuperCollider as a live improvising instrument, most explicitly on the duo and trio records Disklaimer with Hamilton, String Theory with the pianist Ursel Schlicht and Intersections with the Mexican guitarist Omar Tamez.

In 1998 he formed Spooky Actions with the saxophonist John Gunther, a jazz quartet devoted to improvising on twentieth-century classical repertoire. The group recorded Music of Webern (2003), Early Music (2005), a quintet reading of Olivier Messiaen's Quartet for the End of Time (2005) and a Schoenberg program (2007). Alongside it he has produced an unusually large run of guitar duo records, with Mike Miller (Two Guys From South Dakota, Dakota Gumbo), Gilbert Isbin (Invocation, recorded in Bruges), Dusan Bogdanovic (Aspiration), John Stowell (Sonic Infestation), Jane Getter (Secret Code), Barry Wedgle (Gemini), Mimi Fox (Soul Eyes) and, in 2020, Kenny Wessel (Heard Instinct). Since 2014 he has also worked steadily in Sonic Twist, a voice-and-guitar duo with the singer Judi Silvano built entirely on live electronics and in-the-moment improvisation, which has released Listen to This, Cloudwalking, Unity and Dark Forest.

The teaching and the playing meet in his own imprint. Muse-eek Publishing issues both his records and his instruction books, a catalog his current site puts at more than 300 titles covering guitar pedagogy, ear training, music theory and time studies, among them the 700-page Sonic Resource Guide. He has also made instructional video for TrueFire and for Mel Bay, including the 2009 Mel Bay DVD Master Guitar Symposium, Volume 2, which he produced and on which he shares the guitar billing with Roni Ben-Hur, Gene Bertoncini and Wessel.

Arnold's identifying idea, pursued since the early 1990s, is the use of pitch class set theory as an improvising vocabulary: rather than running changes, he treats the twelve-tone material of composers like Anton Webern and Arnold Schoenberg as a source of melodic cells that can be swung, and the Spooky Actions records are that theory made audible by putting a jazz rhythm section under classical repertoire outright. What keeps the approach from turning academic is how physical his guitar playing is. Give 'Em Some and Heavy Mental are loud, distorted power-trio records built on loops and processed guitar, and Bill Milkowski heard in the latter a blend of "visceral rock bombast, jazzy harmonies and cutting edge sonics" that he traced back to Terje Rypdal's mid-1980s band The Chasers; Audio had earlier called Give 'Em Some a raucous power-trio session and Jazziz a frazzled blast of electro-bop. The same writer's ear turns up in far quieter settings, on the acoustic duos with Dusan Bogdanovic and Gilbert Isbin and on the Art of the Blues trio, where the twelve-tone thinking is applied to blues forms. His use of SuperCollider, which lets him process and re-trigger his own playing in real time, gives the free-improvisation side of the catalog a sound that sits closer to electronic music than to guitar-trio jazz. Both his teachers, Charlie Banacos and Jerry Bergonzi, worked from systematic melodic vocabularies rather than from licks, and that habit of mind runs through everything he has written and recorded.