Sergio Armaroli was born on January 27, 1972, in Calcinate, in the province of Bergamo, according to his own biography, and is based in Milan. He trained as both a visual artist and a musician: he studied painting at the Accademia di Belle Arti di Brera in Milan, and percussion, electronic music and jazz at the Conservatorio "G. Verdi" di Milano, with further study at the Accademia della Fondazione Arturo Toscanini in Parma, the Accademia del Teatro alla Scala in Milan, and the Instituto Superior de Arte in Havana, Cuba.

His recording career began on two tracks that have run in parallel ever since. On the contemporary-classical side, he played Scelsi with the Ensemble di Percussioni Naqqara on Collection Vol. 3 (Stradivarius, 2009) and later founded the Empty Words Percussion Ensemble for a multi-volume John Cage project on Da Vinci Classics, where he is credited as curator of the label's "aboutCAGE" series (2019-2023) as well as a performer. On the jazz side, he formed the Axis Quartet, whose debut Prayer and Request (Dodicilune, 2010) and follow-up Vacancy in the Park (2015) paired him with bassist Marcello Testa, drummer Nicola Stranieri and saxophonist Claudio Guida. His first fully solo record, Early Alchemy (2012), and his duo debut with composer Riccardo Sinigaglia, Tecrit (2014), followed on the same label.

Micro and More Exercises (2016) began what has become his longest-running partnership, with trombonist Giancarlo Schiaffini. The two have since built a sequence of thematic projects: a trio with percussionist Andrea Centazzo on Trigonos (2018, reviewed by All About Jazz); a duo recasting Thelonious Monk's tunes through African percussion on Deconstructing Monk in Africa (2021, reviewed by All About Jazz and Citizen Jazz), extended to a quartet with bassist Giovanni Maier on Monkish ('Round About Thelonious) (2022) and a sextet with violinist Emanuele Parrini on Monkian Florilegio (2026); an Albert Ayler counterpart, Deconstructing Ayler in the Universe (2025); and, with saxophonists Harri Sjöström and Veli Kujala added, the two-volume Milano Dialogues quartet, Windows & Mirrors (2022) and More Windows & Small Mirrors (2023), alongside a parallel trio series with Sjöström, Duos & Trios (2020) and More Duos and Trios (2023).

Armaroli has built an equally extensive duo catalogue outside the Schiaffini axis: two records with Swiss percussionist Fritz Hauser, Structuring the Silence (2017) and Angelica (2021); two with American pianist Billy Lester, To Play Standard(s) Amnesia (2017, as a quintet) and Meeting for Two (2020); Dance Steps (2021) with British free-improv drummer Roger Turner; Dialog (2023) with saxophonist Evan Parker, recorded remotely during the pandemic, with Armaroli's Milan-recorded vibraphone improvisations sent to Parker in the UK for his responses; Rib Music (2022), a music-and-text collaboration with British poet Steve Day; and Figure(s) a Due (2024) with bassist Giovanni Maier, extended to a trio with pianist Francesca Gemmo on Figure(s) a Tre the same year. A long-running trio with bassist Steve Piccolo and guitarist Elliott Sharp runs from Blue in Mind (2021) through What Went Wrong (2022) to the two-disc Imaginary Songbook (2025), a set of Great American Songbook reworkings also issued as a 2026 film-studio-session DVD; the same configuration, expanded to a quintet with bassist John Edwards and drummer Mark Sanders, recorded Introducing a Very Heavy Person, First Visit and Follow a Very Heavy Person, First Visit (both 2025) as the Sergio Armaroli Quintet. He has also recorded three unaccompanied vibraphone records, Prismo (2020), Vibraphone Solo in Four Part(s) and Density for Solo Vibraphone(s) (both 2023), and is a member of the Rib Trio, described on his own website as "highly regarded."

His parallel contemporary-classical and sound-art output continued alongside all of this: a realization of Karlheinz Stockhausen's Tierkreis (2024), the field-recording and radio-art releases Mahler (In/a) Cage (Gruenrekorder, 2021), Listen! MadeRadioArt Anthology and OSTN (both Gruenrekorder, 2025), and the duo And I Entered Into Sleep (2025, Die Schachtel) with British sound artist and writer David Toop. His compositions are published by Empty Words Edition, and he has also published books through Mannie Editori. All About Jazz profiled him in a 2022 interview, "Sergio Armaroli: The Musical Omnivore," and has reviewed several of his albums, including The Art of Sound(s) (2025), a quartet led by Swiss drummer Pierre Favre with Centazzo and Gemmo.

Armaroli's work sits mainly in free improvisation and avant-garde jazz: of the 69 release and master entries Discogs credits to him, 49 (71 percent) carry the Jazz genre tag, and of the 48 he leads or co-leads under his own name or one of his small-group entities, 37 (77 percent) are jazz-tagged, with Free Improvisation, Avant-Garde Jazz, Contemporary Jazz and Free Jazz as the recurring styles. The remaining catalogue is a genuine second identity in contemporary classical and sound art: multi-volume engagements with John Cage and Giacinto Scelsi, a Stockhausen realization, and field-recording and radio-art pieces for European experimental labels.

He plays within the European free-improvisation network that also runs through Giancarlo Schiaffini's catalogue, with duo and group credits alongside Evan Parker, Barry Guy, Roger Turner, Fritz Hauser, Harri Sjöström, Veli Kujala, Pierre Favre and Elliott Sharp, and his vibraphone technique frequently extends to prepared vibraphone, balafon and found percussion rather than staying inside the instrument's conventional jazz vocabulary. He is also a trained painter, a graduate of Milan's Brera Academy, and supplies the cover art for several of his own releases (among them Early Alchemy, Vacancy in the Park, Deconstructing Monk in Africa, Vibraphone Solo in Four Part(s) and the Figure(s) duo and trio records), alongside a parallel practice as a published writer.