Marcello Tonolo is a pianist, composer, arranger and educator born January 6, 1955, in Mirano, a small town in the Veneto near Venice. His father, Giancarlo, a socialist who had fought in the Italian Resistance, served as mayor of Mirano from 1970 to 1980; his mother, Elena Erzogy, was Swiss-born and played accordion by ear. Tonolo took piano lessons as a child alongside his younger brother Pietro, who would become a saxophonist and a leading figure in Italian jazz in his own right; the two formed a group together as teenagers, playing local dates around Mirano before pushing on to Milan and the Capolinea, the club at the center of the Italian jazz scene of the era. There Tonolo fell in with fellow Milan-based musicians including guitarist Larry Nocella and drummer Gianni Cazzola, and met alto saxophonist Massimo Urbani.

Tonolo debuted as a leader in 1987 with D.O.C. Denomination of Origin Controlled (Splasc(h) Records), a quartet date with his brother Pietro on tenor saxophone, bassist Piero Leveratto, drummer Alfred Kramer and trumpeter David Boato. The following year he was the pianist, alongside Leveratto, Cazzola and saxophonist Jacopo Jacopetti, on the Gianni Cazzola Quartet's Italian Repertory (1988, Gala Records), contributing the original composition "Round Up"; he later rejoined Cazzola as the pianist on the Massimo Urbani Quartet's live album Live At Belzebù, recorded in 1988 at the Belzebù restaurant in Cazzola's hometown of San Giovanni in Persiceto and issued in 2004. He also appears on two archival Urbani live recordings issued after the saxophonist's death, We'll Be Together Again (2016, recorded 1982 in Rimini) and Live In Mestre Venezia 1982 (2020).

Beginning in 1985, Tonolo and saxophonist Maurizio Caldura Núñez started teaching jazz, founding the Thelonious Monk School of Music in Dolo, near Venice, which Tonolo directed for twenty years; the school became a twin institution of Duke University's Jazz Studies department in Durham, North Carolina, then chaired by tenor saxophonist Paul Jeffrey. Touring visits with students led to a recording made in the United States with Jeffrey and trombonist Curtis Fuller, released as Together In Monaco (1997, credited to the Curtis Fuller/Paul Jeffrey Sextet), on which Tonolo plays piano alongside pianist Jeb Patton. In 1993, the school's twenty-piece student big band, the Keptorchestra, recorded two albums with visiting American saxophonists that Tonolo also played on: Sweet Sixteen, with Steve Lacy, and, three years later, Miss Etna, with Joe Lovano; the Keptorchestra disbanded that same year, 1993, its size having become impractical to sustain. Tonolo also played piano on Piero Odorici's Plays Kurt Weill (1993), a quintet session featuring trumpeter Eddie Henderson, bassist Piero Leveratto and, on drums, pianist Luigi Bonafede - Bonafede's only Discogs-documented credit alongside Tonolo, distinct from a separate, unrelated Discogs anomaly on Cazzola's Italian Repertory that had at one point associated Bonafede's name with that release (see Notes below).

In the 1990s Tonolo led the Music On Poetry project, setting poetry to jazz on Days (1995) and Seed Journey (1998), both on Caligola Records; Days features vocalists Lilian Terry and Carla Marcotulli alongside trumpeters Marco Tamburini and Giampaolo Casati. Tamburini, a trumpeter who died in a motorcycle accident roughly a decade before Tonolo reflected on their partnership in a January 2026 interview, became one of his closest recorded collaborators, including on Amigavel (2004, a duo record) and Isole (2007, Tamburini's own leader session, on which the rhythm section paired Tonolo with American bassist Billy Hart and drummer Cameron Brown - a rare instance on Tonolo's discography of two American sidemen of that stature on the same date). Tamburini went on to teach at the Conservatorio di Rovigo, which later named its auditorium after him.

Tonolo's other big band, the Thelonious Monk Big Band, grew out of the school's arranging workshop from 1997 and recorded Night Over (2007, with trumpeter Giuliano Perin on vibraphone and drummer Davide Ragazzoni) and, later, Note Sui Sillabari (2022) and Sillabari Mood (2026), a project setting the writer Vitaliano Trevisan's readings of Goffredo Parise's Sillabari to music, first staged in 2007 at Parise's house in Salgareda. In the 2010s Tonolo recorded a trio run with bassist Marco Privato and American drummer Jimmy Weinstein, including Lazy Afternoon (2010), Second Take (2012) and Crazeology (2014), the last with guest saxophonist Chris Cheek and trombonist Federico Pierantoni; Pierantoni also appears on Tonolo's Skrjabin In Jazz (2018). Tonolo has recorded frequently with saxophonist Michele Polga and trumpeter Giampaolo Casati through the 2010s and 2020s, including Puccini in Jazz (2014), Skrjabin In Jazz (2018) and Six Friends For Bicio (2025, a tribute to saxophonist Maurizio Caldura Núñez featuring Casati on trumpet). He has also recorded as a sideman for saxophonist Bruno Marini (Bruno Marini 4, 1985) and vibraphonist Giuliano Perin (Flexibility, 2005; Passion & Reason, 2007; I Remember Palladio, 2010).

In 2021 Tonolo and his brother Pietro recorded their first duo album together as co-leaders, Our Family Affair (Caligola), and in 2026 he released a second duo record, Legrand Romance, with vocalist Carla Marcotulli, devoted to the songs of Michel Legrand. He won the 10th International Jazz Orchestra Arrangement Competition in Barga in 1997. Tonolo taught jazz piano at the conservatories of Trieste and Padova - where, by his own account, he was a pioneer of the jazz department, starting with four students and building it to roughly ninety - retiring from his chair at Padova's "Pollini" Conservatory in December 2025. He has also taught at the Conservatorio di Rovigo.

Tonolo is a mainstream, bebop-and-post-bop-rooted pianist whose recorded output ranges from small-group standards dates to big-band composition and arranging; one reviewer described him as a "refined Venetian pianist" and his playing has been characterized as marked by touch and harmonic sensitivity. Composition for large ensembles is a defining thread of his work, from the student Keptorchestra of the late 1980s and early 1990s through the Thelonious Monk Big Band he later founded with Maurizio Caldura Núñez. In the 2010s he turned repeatedly to reworking classical repertoire in a jazz idiom, first Puccini's opera melodies on Puccini in Jazz (2014) and then, on Skrjabin In Jazz (2018), original compositions of his own inspired by the harmonic and color theories of the Russian composer Alexander Scriabin. In a January 2026 interview with Il Gazzettino, Tonolo described jazz as "a freedom that has to be channeled," adding that the deeper a musician's knowledge of the tradition, the freer they become; he named Louis Armstrong, Duke Ellington, Charlie Parker, John Coltrane and Miles Davis among the artists he considers essential listening for any student of the music. In that same interview he described touring Europe with Chet Baker in the final months before the trumpeter's 1988 death and playing with drummer Kenny Clarke; these are first-person, self-reported recollections rather than Discogs-documented studio credits, and given that his brother Pietro Tonolo has an overlapping American-collaborator biography of his own, they are presented here as Tonolo's own account rather than independently verified sessions.