Peter Andrew Bernstein was born September 3, 1967, in New York City. He started on piano at eight, switched to guitar at thirteen, and learned largely by ear before he ever had formal instruction. That changed at Rutgers University, where he studied jazz with guitarist Ted Dunbar and pianist Kenny Barron, and again at the New School in Greenwich Village, where he enrolled as a jazz guitar student in the late 1980s.

It was at the New School that Bernstein met Jim Hall — whose own career, including the full arc of this mentorship, is covered in his JazzProfiles.com profile. Hall invited the young guitarist to appear alongside him, Pat Metheny, and John Scofield at his guitar-summit concert during the 1990 JVC Jazz Festival in New York, a set later released as Live at Town Hall, Volume 2 (1991, MusicMasters, billed to "Jim Hall & Friends"). Hall's liner-note endorsement was unambiguous: Bernstein, he wrote, "has paid attention to the past as well as the future. He is the most impressive guitarist I've heard. He plays the best of them all for swing, logic, feel and taste." For a twenty-two-year-old still enrolled in school, that concert and that sentence amounted to an entrance into the professional jazz world. The same year, alto saxophonist Lou Donaldson hired him, beginning a run of four albums together between 1991 and 1995 that included his recorded debut as a sideman, Play the Right Thing (1991, Milestone).

The 1990s built out fast from there. Bernstein became a first-call guitarist across the New York hard-bop and organ-jazz scene, working steadily with organist Larry Goldings (starting with 1991's Intimacy of the Blues), organist Melvin Rhyne, drummer Jimmy Cobb, and a long list of saxophonists and pianists on the Criss Cross Jazz label's house roster. On December 22, 1992, he recorded his own debut as a leader, Somethin's Burnin' (Criss Cross, released 1993), a quartet date with pianist Brad Mehldau, bassist John Webber, and drummer Jimmy Cobb — Bernstein's first meeting on record with Mehldau, whose own career is covered in full in his JazzProfiles.com profile. The two reconvened in December 1994 for Signs of Life (1995, Criss Cross), this time with bassist Christian McBride and drummer Gregory Hutchinson rounding out the quartet; that same rhythm section regrouped twenty years later, live at Jazz at Lincoln Center, for Signs Live! (recorded January 2015, released 2017 on Smoke Sessions). In 2000, Bernstein, Mehldau, bassist Larry Grenadier, and saxophonist Mark Turner recorded Consenting Adults (Criss Cross) under the collective name M.T.B. — a trio billing that resurfaced twenty-four years later, with Grenadier and drummer Bill Stewart, for the Criss Cross reunion album Solid Jackson (recorded November 2023, released 2024).

Bernstein's own leader catalog grew steadily through the 2000s and 2010s: Earth Tones (1998, with Larry Goldings), Front and Center (2007, co-billed with organist Mel Rhyne), and Monk (recorded at Mo Pitkin's House of Satisfaction and Smalls, released by the newly reactivated Xanadu label in 2008), a trio tribute to Thelonious Monk with bassist Doug Weiss and drummer Bill Stewart. Alongside Goldings, drummer Bill Stewart became the guitarist's other defining long-term partnership: the Goldings/Bernstein/Stewart organ trio, playing together in one configuration or another since the early 1990s, put out Ramshackle Serenade (2014, Pirouet), Toy Tunes (recorded 2016, released 2018, Pirouet) — described on release as the trio's twelfth album in twenty-seven years of collaboration — and Perpetual Pendulum (recorded 2021, released 2022, Smoke Sessions). Bernstein made his own Smoke Sessions Records debut as a leader in 2016 with Let Loose, a quartet date with pianist Gerald Clayton, bassist Doug Weiss, and drummer Bill Stewart, and returned to the label in 2020 for the live quartet session What Comes Next, with pianist Sullivan Fortner, bassist Peter Washington, and drummer Joe Farnsworth.

In 2008 Bernstein joined The Blue Note 7, a septet of label artists assembled for Blue Note Records' 70th-anniversary tour and studio album, Mosaic: A Celebration of Blue Note (2009). His decades-long partnership with Brad Mehldau reached a new chapter in 2024 with Better Angels (Smoke Sessions), a quartet reunion with bassist Vicente Archer and drummer Al Foster recorded the same year as the M.T.B./Solid Jackson reunion — pairing Bernstein and Mehldau on record in two different bands within months of each other, more than three decades after Somethin's Burnin' first put them in a studio together.

Bernstein has also recorded with saxophonist Joshua Redman, pianist Diana Krall, organist Dr. Lonnie Smith, trumpeter Tom Harrell, and saxophonist Lee Konitz — whose own career is covered in full in his JazzProfiles.com profile. Konitz and Bernstein had grown up as neighbors in the same New York apartment building and had talked for years about recording together before finally doing so on Konitz's Parallels (2001, Chesky Records), alongside guest saxophonist Mark Turner. Bernstein teaches jazz guitar at New York University's Steinhardt School and continues to teach at the New School, the same program where his own career began.

Bernstein's guitar sound is warm, unhurried, and harmonically direct — shaped first-hand by Jim Hall's mentorship and by a stated preference, echoed by Hall's own approach, for logic and space over speed. He has played a 1981 Zeidler archtop guitar for most of his recording career, and his working vocabulary sits comfortably across both the organ-combo hard-bop tradition (Goldings, Rhyne, Dr. Lonnie Smith) and the more harmonically exploratory post-bop side of his catalog with Mehldau and Turner. That range — equally at home swinging behind an organ trio or trading lines inside Mehldau's more chromatic writing — is a large part of what made him one of the most in-demand sidemen of his generation as well as a distinctive leader in his own right.