Julia Feldman was born into music. Her grandfather, Solomon Feldman, led Samara's city philharmonic orchestra as a conductor for more than twenty years, and her father, Ilya Feldman, plays jazz piano alongside his day job as a jewelry designer. Feldman started classical piano at five, and kept studying it right up until 1990, when her family immigrated to Israel and settled in Jerusalem. There she continued piano with Anatoly Tartakovsky and picked up jazz improvisation with composer and saxophonist Stephen Horenstein at Jerusalem's High School of Arts.

Jazz singing caught her in her final year of high school. In 1997 she began studying voice technique and jazz improvisation with Israeli jazz vocalist Iris Portugaly, alongside intensive jazz study under saxophonist Arnie Lawrence at Jerusalem's International Music Center. Lawrence's center put her in the room with visiting American musicians, including Larry Goldings, Sheila Jordan, Judi Silvano, Armen Donelian, Evelyn Blakey, and Bob Meyer, and she was invited to sing composer Allen Gershwin's "Walk in the Wilderness" at a concert honoring his father, George Gershwin. She kept studying vocal jazz with Portugaly at the Rimon School of Jazz and Contemporary Music through 1998 and 1999, then graduated the Jerusalem Academy of Music and Dance in 2003, where her teachers included opera singer Robin Weisel-Capsouto for voice, vocalist Ataliya Pniel for jazz improvisation, and composer Vyacheslav "Slava" Ganelin for composition. That same year, the Jerusalem Post profiled her as part of what it called the city's "off-beat trio."

With pianist Yitzhak Yedid and double bassist Ora Boasson-Horev, Feldman formed the Julia Feldman Ensemble and released its debut, Words Are Worlds (A Tribute to Billie Holiday), on the major Israeli label Hed Arzi in 2006. The album reworks jazz standards associated with Holiday, tied together by a recurring motif from Holiday's "God Bless the Child," and drew a real critical response: Haaretz's Ben Shalev called it "an extraordinary work that tries to meet the spirit of the original, not to imitate it," while noting Feldman "does not yet have the presence of a great singer." All About Jazz's Eyal Hareuveni singled out her rendering of "Strange Fruit" as reverential and her take on Ornette Coleman's "Lonely Woman" as ambitious, if "too cerebral." The same year, the ensemble contributed the track "Ze Kore" to the various-artists compilation Jazz in Jerusalem Project: Birth of the Local Standard.

By 2007, Haaretz's feature on Jerusalem's small jazz scene picked out Feldman's ensemble as one of only two Jerusalem-based groups selected for that year's Tel Aviv Jazz Festival, alongside drummer Nadav Haber's quartet. The piece traced the city's jazz "renaissance" back to Arnie Lawrence's arrival, and quoted Feldman on the idea behind her album: "It's really a fantasy. If we were to take Holiday's amazing development and roll it forward in time, what would happen?"

Feldman also led a second group, the Julia Feldman Jazz Quartet, co-founded with Israeli guitarist Steve Peskoff, performing her own compositions and standards arrangements shaped by rock, funk, Brazilian music, and free improvisation across Israeli stages and festivals. In February 2008 she and Peskoff traveled to New York to record the quartet's debut, joined by drummer Ferenc Nemeth, bassist Massimo Biolcati, vocalist Ayelet Rose Gottlieb, and saxophonist Loren Stillman; per Peskoff's own account, that session was never released.

Alongside her two named groups, Feldman kept a busy sideline of collaborations: lead singer in the progressive rock band Musica Ficta, led by guitarist Ehud Horev; vocalist in Peskoff's Radical Shlomo project, arranging the songs of Shlomo Carlebach; pianist, vocalist, and co-writer with Ayelet Rose Gottlieb in the duo Ayulyul; a voice-and-double-bass duo with Eli Magen; and work with the Jerusalem ethno-core band Shoom. She sang backing vocals on singer-songwriter Tomer Bar's 2010 Hebrew-language album Ani Shafan Blues, and again in 2013 on Ayelet Rose Gottlieb's album Roadsides, where she is credited alongside pianist Anat Fort, also singing backing vocals on that record. That same year, Feldman appeared as a guest vocalist at a Boris Gammer Sextet concert at the Jerusalem Cinematheque, one of the last documented public performances found in researching this profile. No further activity has been confirmed since; her official website, julia-feldman.com, no longer resolves.

Feldman's whole recorded debut is built around Billie Holiday, not as an act of imitation but, in her own words, an attempt to imagine "Holiday's amazing development... rolled forward in time." Her choice to cover Ornette Coleman's "Lonely Woman" on that same album signals a free-jazz vocabulary sitting inside a piano-trio-plus-voice format more commonly reserved for standards. Wikipedia categorizes her among free jazz singers, and Discogs tags Words Are Worlds itself as Post Bop. Her composition training under Vyacheslav Ganelin, a figure associated with Soviet-era free jazz and avant-garde composition, sits logically behind that same instinct toward reworking rather than replicating a source. Reviewers have praised her interpretive courage even while noting, as Haaretz did in 2007, that her vocal presence was still developing at the time of her debut.