Klein hails from Southern California, and undertook formal musical training. His vocation was inspired by an after-school musical program at The Community Schools at U.S.C. It enabled him to hone his playing and compositional skills with university professors while attending high school. While attending college at Cal State, he worked in various jazz and Latin groups, including five years touring with top-flight jazzmen Freddie Hubbard, Wayne Shorter, Joe Henderson, and Willie Bobo. He began his production career by releasing a pair of singles by the funk outfit Catch on his own LK Records label, and first teamed with Mitchell to record 1982's Wild Things Run Fast, becoming her husband that same year. He acted as her producer with the 1985 album Dog Eat Dog, an album which also heralded the beginning of his exploration of synthesizers and contemporary programming techniques. His work with Mitchell also led to high-profile sessions with Don Henley (1984's Building the Perfect Beast), Peter Gabriel (1986's So), and Robbie Robertson (his long-awaited 1987 solo debut), as well as productions for ex-Cars bassist Benjamin Orr (1986's The Lace) and the Innocence Mission (their eponymous 1989 debut). Klein's third record with Mitchell, Chalk Mark in a Rain Storm, appeared in 1988; Night Ride Home followed in 1992. In the process of recording 1994's Turbulent Indigo, the couple's marriage dissolved; Klein subsequently went on to work with Holly Cole, Mary Black, Rodney Crowell, Shawn Colvin, and Julia Fordham. Klein also contributed to the soundtrack of the 1996 film Grace of My Heart. In 1997 he co-produced the Dinosaur Jr. single "Take a Run at the Sun," with J. Mascis, Kyle Eastwood's debut offering From There to Here, and Lynn Miles' Night in a Strange Town. Klein never strayed far from jazz, however, as his work with Cole suggests, but in 1999, he also produced Chris Botti's breakthrough album Slowing Down the World. At the dawn of the 21st century, he helmed two more projects by Mitchell -- Both Sides Now and Travelogue. He began producing Peyroux with her sophomore outing Careless Love in 2004, and has helmed all but two of her albums since. In 2006, he produced German trumpeter and vocalist Til Brönner's charting Oceana for Verve and Souza's The New Bossa Nova -- the two were married that year. 2007 saw Klein produce Hancock's River: The Joni Letters, whose singers included Peyroux, Norah Jones, Tina Turner, Corrine Bailey Rae, Leonard Cohen, and Mitchell herself. It peaked at number five on the Top 200, and charted in four European countries. At the 50th annual Grammy Awards, it became only the second jazz album to win Album of the Year. (The first was 1965's Getz/Gilberto by Stan Getz and João Gilberto.) The following year Klein was a hot property: He worked on no less than eight albums across the genres including the soundtrack for Crazy, Walter Becker's Circus Money, Bronner's Rio, and Rebecca Pidgeon's Behind The Velvet Curtain. These dates do not include his wealth of credits as a studio musician he amassed the same year. In 2009 Klein and Souza teamed again for Tide and he helmed the sessions for French vocalist Eddy Mitchell's Grand Ecran, Raul Midon's Synthesis, and Melody Gardot's international breakthrough album My One and Only Thrill.
In 2011, Klein produced and played bass on Pidgeon's masterpiece, Slingshot, and co-wrote eight of its 12 tracks. Over the next few years he branched out internationally. He produced Anna Bergendahl's Something to Believe In, Dybdahl's What's Left Is Forever, Ana Moura's Desfado, Otis Brown III's The Thought of You, Mitchell's Héros, and Billy Childs' acclaimed Map to the Treasure: Reimagining Laura Nyro. In 2015, Klein produced Lizz Wright's hit offering Freedom Surrender, Lisa Bassenge's Canyon Songs, Gardot's Currency of Man, and Souza's widely celebrated Speaking in Tongues.
In 2016, Klein branched into classical by producing Lang Lang's New York Rhapsody as well as Kandace Springs' Blue Note debut, Soul Eyes. The following year saw one of Klein's most ambitious and audacious projects released: The Passion of Charlie Parker. The double-length release is the story of the great, tragic altoist via a noirish, radio-play narrative through the voices of top-flight singers including Peyroux, Jeffrey Wright (as Parker), Gregory Porter, Kurt Elling, Barbara Hannigan, Souza, and Springs, as well as instrumentalists including Donny McCaslin, Craig Taborn, Ben Monder, Eric Harland, Scott Colley, and Larry Grenadier. In addition to this massive outing, Klein also produced Hailey Tuck's hit debut long-player Junk. There was no slowdown for the producer in 2018. The year saw him involved in production, performance, and songwriting on five widely acclaimed albums. While Souza's Leonard Cohen project, Book of Longing, may have been his most intimate project, he helmed Peyroux's universally acclaimed Anthem, actor/pianist Jeff Goldblum's hard-grooving jazz debut The Capitol Studios Sessions with the Mildred Snitzer Orchestra, Dybdahl's conceptual, dark portrait of L.A. titled All These Things, and Canadian pop-jazz singer Molly Johnson's Meaning to Tell Ya. ~ Jason Ankeny, Rovi