Kahane was born in Los Angeles in 1981. The son of pianist and conductor Jeffrey Kahane, he was raised on both coasts. He studied music beginning at age seven, singing in a Catholic boys' choir. His parents' musical tastes ran the gamut from classical to Paul Simon and other pop acts, which influenced his cultural worldview considerably.
He attended college at the New England Conservatory of Music where he majored in jazz studies, and later attended Brown University, where he wrote his first musical "on a lark" and became deeply attracted to the form.
His first nationally noticed work was 2006's Craigslistlieder, for voice and piano. Using eight ads from the website, he created a song cycle that he performed on piano and voice. It was followed in 2007 by Caravan Man, a one-act theater ensemble work commissioned by the Williamstown Theater Festival.
Other major works that pre-date his first recording are For the Union Dead, a chamber and vocal work based on the poems of Robert Lowell, 2009's Django: Tiny Variations on a Big Dog, for piano — commissioned by his father — and Pocket Concerto, for solo trumpet, flute, clarinet, and string trio (with violin doubling as electric guitar), as well as 2010's Étude: Cobalt Cure for solo violin commissioned by Festival Vestfold, and The Red Book, composed for the Kronos Quartet, based on Anne Carson's novel-in-verse Autobiography of Red.
In 2011, Kahane recorded Where Are the Arms, his debut collection of songs for Second Story Records. It featured performances by Sufjan Stevens, Sam Amidon, and Chris Thile. That same year, he also contributed to Beautiful Mechanical, a collection of songs by younger composers who included Ryan Lott, Annie Clark, Shara Worden, and Sarah Kirkland Snider. He composed and performed The Memory Palace for baritone and piano, commissioned by New York Festival of Song, and Come on All You Ghosts for string quartet and baritone, commissioned by Bravo! Vail Valley Chamber Music Festival for the Calder Quartet. The widely acclaimed Orinoco Sketches for large chamber ensemble and soloist was commissioned by the Los Angeles Philharmonic and conducted by composer John Adams.
February House, a two-act musical theater piece, with a libretto by Seth Bockley, was premiered at the Public Theater in New York in 2012 with an ensemble cast. It was set at 7 Middagh Street in Brooklyn Heights in an artist's commune founded by author/editor George Davis and Gypsy Rose Lee in 1940. The title refers to Anais Nin's nickname for the location as so many of its residents — including Benjamin Britten, Peter Pears, Carson McCullers, W.H. Auden, and Erika Mann — had February birthdays. The cast recording became Kahane's second album and was issued on Storysound Records in October.
This wasn't the only work Kahane delivered in 2012. The Fiction Issue for string quartet, piano, reed organ, two guitars, two solo voices (one male/one female) was commissioned by Carnegie Hall for the composer, Brooklyn Rider and Worden, and Crane Palimpsest for baritone and chamber orchestra (the latter was co-commissioned by the American Composers Orchestra and the Los Angeles Chamber Orchestra).
A signature work appeared in 2013: Gabriel’s Guide to the 48 States, for baritone, electric guitar, banjo, and chamber orchestra, commissioned by Orpheus Chamber Orchestra.
That same year, Kahane signed to Sony Masterworks and began composing his debut for the label. The Ambassador, an episodic song cycle about the City of Los Angeles, was inspired by ten of its buildings. Co-produced by Casey Foubert, Matt Johnson, and Rob Moose, it featured guest vocals by Worden and Aiofe O'Donovan, and the instrumental contributions of a host of the brightest young classical musicians on the scene. The Ambassador was issued in June of 2014. After a falling out with Sony Masterworks over its handling of that album, which ended in Kahane negotiating a release from his contract and buying back rights to the follow-up, he went the D.I.Y. route for his next LP. A collaboration with acclaimed string quartet Brooklyn Rider, The Fiction Issue arrived in early 2016 and marked the musician's first appearance on Billboard, hitting number three on the Traditional Classical Albums chart. It comprised a two-character "miniature drama" with guest Shara Worden (My Brightest Diamond), a vocal work featuring three poems by Matthew Zapruder, and an expanded version of one of his songs from The Ambassador. Kahane returned to working with a label for his next effort. Nonesuch released Book of Travelers in 2018 after the record began life as a song cycle that he performed at BAM. It was originally conceived on a road trip he undertook following the 2016 presidential election with no phone or internet, and was largely inspired by strangers he met along the way.