She rose to fame as part of synthesizer trio Au Revoir Simone and their collaborations with David Lynch, Air, and many others.

[4] Hart was born on Long Island, New York, and is one of three founding members of synth-pop group Au Revoir Simone.

She has been in other groups including Uninhabitable Mansions,[5] featuring members of Clap Your Hands Say Yeah,[6] and collaborated as a composer with French band Air for their soundtrack to Les Voyages Dans La Lune.

Her song "Hard To Be Still" appeared on episode one of the Netflix series Gypsy, starring Naomi Watts.

[10] Hart's music is considered minimal synth-pop, which New York magazine's Bedford and Bowery describes as "resonant, tender, and not too sweet".