Barbara Casini was born in 1954 in Florence. She studied piano as a child and was introduced to bossa nova at age 15, an encounter she has cited ever since as the turn that set her musical direction. She earned a degree in psychology from the University of Padova before committing to music, and began performing professionally in 1979. In the years that followed she spent extended periods living and working in Brazil, building a reputation there substantial enough that Brazilian musicians and critics have described her as a de facto ambassador for their own popular music abroad; the anecdotal recognition includes praise from Chico Buarque and Milton Nascimento, both of whom she would go on to work with directly.

Her recorded debut as a leader, Todo O Amor (1997, Philology), already shows the two threads that run through her whole catalog: Brazilian repertoire and Italian jazz personnel. The album carries liner notes from Enrico Rava and a piano and arranging credit from Stefano Bollani, alongside soprano saxophonist Stefano Cantini, flutist Riccardo Luppi, and percussionist Naco - the same percussionist with whom, together with guitarist Beppe Fornaroli, she had earlier formed the trio Outro Lado in the early 1980s, eventually documented on record in 2000.

The turn of the millennium brought her two most explicitly orchestral projects, both arranged by Paolo Silvestri: [Vento] (2000, Label Bleu), co-billed with Enrico Rava and scored for a full chamber orchestra (strings, winds, and brass drawn from Milan's Accademia Filarmonica della Scala circle), with Stefano Bollani doubling on piano and vocals and Giovanni Tommaso and Roberto Gatto anchoring the rhythm section; and, a decade later, Agora Tá (2012, Via Veneto Jazz), scored for the Orchestra Jazz della Sardegna big band.

Her most concentrated run of straight-ahead jazz credits comes from a single week: the Umbria Jazz Festival, July 15-17, 2003, where she guested as vocalist across a trio of live albums built around Lee Konitz, Phil Woods, and Enrico Rava, all released on Philology in 2004. Play Rava pairs Konitz and Woods (both alto saxophone) with Rava (trumpet and flugelhorn), Stefano Bollani (piano), Ares Tavolazzi (bass), and Roberto Gatto (drums), with Casini singing lead vocal; the companion volumes Play Woods and Play Konitz, drawn from the same festival week but built around a Woods/Konitz quintet with pianist Andrea Pozza, bassist Massimo Moriconi, and drummer Massimo Manzi, carry the same arrangement. A year earlier, Outra Vez (2002, Philology) had paired her in a more intimate format directly with Lee Konitz: a bossa-nova-repertoire session on which, per JazzTimes' review, Konitz answers her vocal with a scat chorus and a vocal obbligato of his own.

Her Brazilian-repertoire catalog runs in parallel and includes full-length tributes and monographic readings: Palavra Prima (2006, Philology), built around the songs of Chico Buarque, with Buarque himself credited as the songs' author; Barato Total (2011, Philology), a tribute to Gilberto Gil; Uragano Elis (2004, Via Veneto Jazz), a tribute to Elis Regina featuring pianist Dado Moroni; Uma Mulher (2015, Philology), with pianists Alessandro Lanzoni and Seby Burgio; Terras (2016, Via Veneto Jazz), a duo record with Brazilian-Honduran guitarist Roberto Taufic (Duo Taufic); and Viva Eu (2020, Encore Music), recorded in Rio de Janeiro with guitarist Toninho Horta and a guest list of MPB figures including Chico Buarque, Edu Lobo, and Joyce Moreno. A more recent trio project, Hermanos (recorded 2021-2022, Encore Music) with Argentine reedman Javier Girotto, Roberto Taufic, and pianist Seby Burgio, widens her repertoire beyond Brazil into the broader Latin American songbook (Peru, Cuba, Venezuela, and Argentina among the sources), and was reviewed in the Italian jazz press by Musica Jazz.

Elsewhere in her catalog, Angoli Confusi (2006, Double Stroke) is a trio billing with pianist Alessandro Galati and saxophonist Pietro Tonolo; Formidable! (2009, Philology) sets the songs of French chansonnier Charles Trenet with bassist Ares Tavolazzi and trumpeter Fabrizio Bosso; and Gershwin & More (2005, Philology) and the undated Un Anno D'Amore (Philology) are duo records with veteran pianist Renato Sellani. In 2012 she published Se Tutto È Musica (Angelica Editore), a book gathering conversations with major Brazilian composers about their own creative process, illustrated with photographs from her trips to Brazil and shaped in part by musician Novelli, who knew many of the interviewees personally.

Casini's catalog sits at the intersection of Italian jazz and Brazilian popular song. Discogs' own genre and style tags for her records split cleanly along that line: releases like [Vento], Gershwin & More, Angoli Confusi, Formidable!, and the Umbria Jazz live dates carry a plain "Jazz" genre tag (with "Bop," "Cool Jazz," and "Contemporary Jazz" among the recurring styles), while her more purely Brazilian-repertoire records - Sozinha, Outro Lado, Palavra Prima, Luiza, Viva Eu - are tagged "Latin"/"MPB" instead. Rather than smoothing that split over, it reflects two genuinely distinct wings of one career: a bossa-nova-and-MPB specialist practice built on direct experience in Brazil, running alongside a documented, credit-level presence in Italy's own jazz mainstream, most concentrated in her week-long Umbria Jazz Festival collaboration with Lee Konitz, Phil Woods, Enrico Rava, and Stefano Bollani, and in duo and trio work with pianists Renato Sellani, Dado Moroni, Alessandro Lanzoni, and Alessandro Galati.