Mirio Cosottini plays trumpet and flugelhorn inside Italy's free improvisation scene, a corner of the jazz world built less around standards than around real-time invention with a small, recurring circle of collaborators. He was born September 9, 1971, in Figline Valdarno, Tuscany, and trained classically first: a trumpet diploma from the Conservatorio di Firenze "Luigi Cherubini," followed by advanced study with French trumpeter Pierre Thibaud.

His turn toward improvised music came through Timet, an experimental collective he joined in 1996 and worked within until 2002 as performer, composer, and music theorist. Timet put him in the same room as a wide circle of Italian and international musicians, among them pianist Stefano Bollani and bassist Ares Tavolazzi, both credited alongside Cosottini on the Discogs listing for the Timet albums Restituzioni (1999) and, in Bollani's case, also Carne Capitata (2000). The same period brought him into contact with trumpeter Enrico Rava and pianist Stefano Battaglia, among others, though no recording together with either is documented at the Discogs credit level.

Alongside music, Cosottini pursued philosophy in parallel: a degree from the University of Florence in 1999, and a 2019 doctorate in History of Societies, Institutions and Thought from the Medieval Era to the Contemporary Age, with a dissertation on the phenomenology of musical improvisation from the performer's perspective. He taught Musical Improvisation at the Conservatorio di Padova from 2005 to 2010, alongside improvisation workshops at conservatories in Cesena and Florence and at Berlin's Exploratorium, and has since taught at a secondary school in the Arezzo area. He has also published two books on improvisation and the philosophy of silence, Playing with Silence (Mimesis International, 2015) and Metodologia dell'Improvvisazione Musicale (ETS, 2017), plus essays in journals including Perspectives of New Music and Musica Domani.

His recorded catalog centers on a long-running duo with New York-based pianist Tonino Miano, begun in 2008: The Curvature of Pace (2008), the quartet session Cardinal (2009, with bassoonist Alessio Pisani and drummer Andrea Melani), and The Inner Life of Residue (2013), an album All About Jazz called more squarely rooted in a jazz idiom than the duo's earlier work. In 2014 he began a parallel duo with Austrian pianist Reinhard Gagel, resulting in Pieces Without Memory (2015), built from quiet, unhurried real-time dialogue developed over three years of joint practice in Vienna, Cologne, Arezzo, and Berlin. He also co-founded the trio ElectroAcousticSilence (with bassoonist Pisani and electronics player Luca Cartolari) in 2009, later expanded into the EAOrchestra and the quartet Tidal, and has contributed trumpet to several film-adjacent projects by composer Arlo Bigazzi, including Tribae Soundtrack (2018) and Short (Pieces for Short Movies) (2023).

Musica Jazz magazine's year-end Top Jazz critics' poll named him best brass instrumentalist in its 2008, 2009, and 2010 rankings, with Cono di Ombra e Luce (2009) and Flatime (2010) also placing among the poll's albums and ensembles of the year. His work has drawn reviews in All About Jazz and the Free Jazz Collective, alongside occasional session work outside jazz entirely, including a 2003 studio credit on singer Irene Grandi's Prima di Partire.

Cosottini's playing sits inside European free improvisation rather than the standards-and-changes tradition, built on real-time listening and restraint over displays of technique. A recurring idea in his own writing and in reviews of his records is "invariance," the notion that a sound's essential character can persist even as it is transformed, and reviewers have repeatedly noted a preference for space and quietness over filling it. His two main duo relationships pull in different directions: with Tonino Miano toward chamber-like, harmonically grounded playing that critics have called his most jazz-idiomatic work, and with Reinhard Gagel toward sparer, more purely abstract sound-dialogue. Outside his own leader dates, he has scored extensively for Italian theater and dance productions and worked within classical and electroacoustic contexts, reflecting a career built as much around composition and pedagogy as around performance.