Brennan was born in
Dublin, Ireland. His family moved to
Switzerland when he was seven years old. He began taking piano lessons at age eleven, played bass guitar in a rock band in 1970, then played keyboards in a jazz-rock band. He studied at the
University of Fribourg (late 1970s),
Swiss Jazz School in
Bern (1975–79), the conservatory in
Lucerne (1979–84), and the Academy of Church and School Music (1985–87). His brother Peter Wolf, a singer, saxophonist, flautist, and oboist, founded the progressive rock band Flame Dream in 1977. During the same year Brennan founded the
free jazz group Freemprovisations, which included
Peter Schärli. Two years later he formed the band Impetus.
From 1980 to 1984, he played in Impetus and the Mohrenkopf Afro-jazz band from 1980 to 1982 in Triumbajo with Ushma Agnes Baumeler and Barni Palm. During the 1980s he also worked with
Corin Curschellas,
Christy Doran, and
Urs Leimgruber. In 1988, he worked in
New York City for six months, then founded the quartet Pago Libre the following year.
Early in the 1990s he worked with
Lindsay Cooper, Daniele Patumi, and Tscho Theissing and established the SinFONietta ensemble in 1991. In 1993, he worked with American drummer
Alex Cline in the quintet Shooting Stars & Traffic Lights. Russian hornist
Arkady Shilkloper joined Pago Libre and recorded the albums Pago Libre (1996), Stepping Out (2006), PlatzDADA! (2008) and Fake Folk (2009).
Brennan worked with clarinetist Gene Coleman for the Momentum albums and with Christy Doran and Patrice Heral in the group Triangulation, where he developed "comprovisation", a term he coined in 1989. He released the solo albums The Beauty of Fractals (1989), Pictures in a Gallery (2006), and The Speed of Dark (2009). Following his album The Well-Prepared Clavier (1998), he developed prepared piano techniques, creating non-electronic sounds such as "arcopiano", "pizzicatopiano", "tamburopiano", and "sordinopiano".
In 2010, he created the sound installation "Inner & Outer Spaces" with video artist Susanne Hofer for the Lucerne Art Museum, performing with
Gerry Hemingway and Thomas K. J. Mejer. He was in the trio Melos Montis with Hanspeter Wigger and yodel singer Franziska Wigger and in the duo Twinkeys with Esther Flückiger. He formed the band Sonic Roots with Christy Doran, Andreas Gabriel, Marc Halbheer, Heiri Kaenzig, and Marcel Oetiker.
In 2012, he collaborated with overtone singer Christian Zehnder and Arkady Shilkloper. During the same year he recorded Pilgrims with guitarist Marco Jencarelli and percussionist Tony Majdalani. In 2018, he founded the trio SOOON with Majdalani and yodel singer Sonja Morgenegg.
Brennan has composed film music, chamber music, and the operas Güdelmäntig (2004) and Night.Shift (2007, based on the poem "The Age of Anxiety" by
W. H. Auden). The first volume of his Sonic Roots series of books (for piano, inspired by Celtic Country Dances) was premiered at the
Frankfurt Book Fair in 2010 and published by Pan-Verlag. The second and third (for violin) were published in 2011, the fourth (for clarinet) in 2013, the fifth (for alto saxophone) in 2014.
The Percussion Art Ensemble Berne premiered his composition "Oscillating Orbits" in 2013 for marimba, vibraphone, timpani, and percussion featuring violinist Misa Stefanovic. In 2015, the Neues Orchester Basel commissioned "Traumpfade", a piece for orchestra and overtone soloist Christian Zehnder. For the 30-year anniversary of the Zurich James Joyce Foundation he wrote "Winds of May" for soprano and piano based on Joyce's Chamber Music IX. He wrote a hymn for his Swiss hometown,
Weggis, called "s'Wäggiser Lied". For the Alpentöne Festival 2017, he composed "Got hard", an alpine jazz suite for wind orchestra, Pago Libre & Friends (released by Leo Records in 2018). In August 2018, the
Tonhalle Orchester Zürich performed his work Traumpfade with soloists Arkady Shilkloper (alphorn) and Christian Zehnder (overtone voice, global yodeling) at the Festival Stubete am See.
In 2019, he wrote most of the choir arrangements for the program Inland by the Zurich female choir "die vogelfreien". He composed music for the play Fluctus and released the albums Nevergreens, Cinémagique 2.0, and Youchz.
2016: Echo. Von der Suche nach Widerhall. Feature by Bettina Mittelstrass, with
Christian Zehnder & John Wolf Brennan. Featureprice 2016 (Christoph Merian Verlag)
2023: Klanglabor feat. John Wolf Brennan (Vinyl; Little Big Beat) with Arno Oehri, Denise Kronabitter & Marco Sele
2024: Percussion Art Ensemble Bern & Misa Stefanovic: Grenzgänger Works by
Fred Frith, John Wolf Brennan & Siegfried Kutterer
Groupe Lacroix
1997: The Composer Group (Creative Works Records) with Moscow Rachmaninov Trio
1999: Arpiade (edition edex) with Barbara Sutter, Béatrice Wolf & Michael Wolf