As a solo soprano, Josephine sang in a performance of Philip Glass's epic Music in Twelve Parts led by James McVinnie at the Barbican (2017), in Morton Feldman's Rothko Chapel with LCO soloists at the Roundhouse (2016), in George Aperghis's La Nuit en Tête with Explore Ensemble at the Royal College of Music (2016), and in Berio's O King with the Bristol Ensemble at Bristol's Elektrostatic festival (2012). She was Irma in Tom Phillips's opera IRMA with Apartment House directed by Netia Jones (South London Gallery, 2017), and has premiered roles in operas by Anton Lukoszevieze, Kate Whitley and Joel Rust. She also sang in artist Laure Prouvost's They Are Waiting For You (a collaboration with Sam Belinfante and Pierre Droulers) during the Performatik festival at Brussels's Kaaitheater (2019).
Her solo voice can be heard on records by Jon Hopkins, Hayden Thorpe, Ex:Re, Lokki and Strange Boy, as well as in films How To Talk To Girls at Parties (2017, directed by John Cameron Mitchell, music by Nico Muhly) and Nome di donna (2018, directed by Marco Tullio Giordana, music by Dario Marianelli).
As an ensemble singer, Josephine regularly performs with UK leading choirs including Tenebrae, The Tallis Scholars, EXAUDI, The Erebus Ensemble, Philharmonia Voices and Britten Sinfonia Voices. With the London Contemporary Orchestra, she has sung on Radiohead's latest album A Moon Shaped Pool (2016) as well as on Thom Yorke's score for Luca Guadagnino's 2018 film Suspiria. She is a founding member of vocal ensemble SHARDS, frequent collaborators with Erased Tapes artists including Nils Frahm.
Josephine was part of the Maîtrise de Radio France, the French radio children's choir, as a teenager, and was a choral scholar at Clare College, Cambridge as an undergraduate. Whilst at Cambridge she sang the roles of Yniold in Debussy's Pelléas et Mélisande with the Cambridge University Opera Society, and Filia in Carissimi's Jephte with Clare College Choir.