Peter Anderson was born March 27, 1987, in Washington, D.C., ten minutes before his identical twin brother Will, and the two were raised in nearby Bethesda, Maryland, where they attended Walt Whitman High School. Both boys were drawn to jazz as teenagers, mentored locally by the saxophonist Paul Carr and by the drummer and vibraphonist Chuck Redd; while still in high school they toured the United Kingdom, performed on Capitol Hill, and appeared on television. At eighteen they moved to New York to attend the Juilliard School, earning a Bachelor of Music (2005-2009) and a Master of Music (2009-2011) and studying under Joe Temperley, Victor Goines, Frank Wess, Benny Golson, Kenny Washington, and Joe Wilder. Both brothers held the Illinois Jacquet Scholarship in Jazz Studies at Juilliard from 2007 to 2009, and during their undergraduate years they were selected from an international pool for Betty Carter's Jazz Ahead program, which included a residency of performances at the Kennedy Center. Discogs's own artist biography for Peter specifically credits him as the twin who "primarily plays tenor sax and clarinet," against Will's alto saxophone, clarinet, and flute, a distinction later confirmed on session after session; press coverage has also noted that Peter is the one born ten minutes earlier and Will the taller by an inch and a half.

Peter and Will made their recording debut as leaders with Correspondence (Smalls Records, 2012), a quartet date with three of their Juilliard mentors, pianist Kenny Barron, bassist Ben Wolfe, and drummer Kenny Washington; Vanity Fair named it alongside new releases by Miles Davis and Wayne Shorter in a piece on records to "make you love jazz." The following year brought Music of the Soprano Masters (Gut String Records, 2013, catalog GSR 011), on which the twins are joined by the veteran soprano saxophonist and clarinetist Bob Wilber and by pianist Ehud Asherie, whose own Discogs page lists "Anderson Twins Sextet" among its group affiliations, the fact connecting this profile to Asherie's. That sextet billing documents a real, separately recorded unit: Asherie, Peter, and Will, alongside bassist Clovis Nicolas, drummer Kevin Dorn, and trumpeter Jon-Erik Kellso, self-released Celebrating the Music of Artie Shaw and Benny Goodman (2010), the sole release credited to the group entity. The brothers went on to record as the Peter and Will Anderson Trio with guitarist Alex Wintz on Reed Reflections (Gut String Records, 2014, GSR 016), reviewed by the Washington Post, then returned to full-quintet dates with A Sax Supreme (SteepleChase LookOut, 2015, SCCD 33122), featuring Ken Peplowski and Grant Stewart alongside Asherie, and Deja Vu (Gut String Records, 2015, GSR 020), an all-originals record with drummer Albert "Tootie" Heath praised by JazzTimes as "a burner that reveals the band's cohesiveness and spirit."

Alongside the recording career, the brothers created, produced, and starred in a series of off-Broadway shows at Manhattan's 59E59 Theaters built around specific songbooks and eras: Le Jazz Hot (how the French saved jazz), The Count Meets the Duke, The Fabulous Dorseys, and Joy of Sax, eventually totaling five (and, per some accounts, eight) sold-out runs; Le Jazz Hot was nominated for the 2014 Drama Desk Award for Outstanding Revue. The working group continued to record through the second half of the decade: Two Against One (Gut String Records, 2016, GSR 021), featuring guitarist Felix Lemerle; Clarinet Summit (SteepleChase LookOut, 2017, SCCD 33133), pairing the twins on clarinet with Ken Peplowski and the Cuban-born clarinetist and saxophonist Paquito D'Rivera; Blues for Joe (Gut String Records, 2017, GSR 026), dedicated to their late Juilliard mentor Joe Temperley and featuring guitarist Peter Bernstein and organist Pat Bianchi; and Wind Power (Gut String Records, 2018, GSR 035), again with Lemerle. After Temperley's 2016 passing, the brothers raised more than $25,000 to establish the Joe Temperley Juilliard Student Scholarship Fund and an accompanying tribute album.

Peter's sideman work outside the duo is real but thinly documented on Discogs relative to the joint catalog, and Discogs itself splits his sideman credits across at least three separate artist entities under slightly different name renderings ("Peter Anderson (10)," "Peter R. Anderson," and "Peter Reardon Anderson," the last evidently drawing on an actual middle name), a split this profile traced out rather than assumed. Under those combined entries, Peter (credited on reeds, separately from Will) appears on singer-songwriter Loudon Wainwright III's I'd Rather Lead a Band (2020), a set of vintage pop and jazz standards backed by Vince Giordano and the Nighthawks; on trombonist Wycliffe Gordon's film score Within These Gates of Mine (Blues Back Records, 2016), playing tenor saxophone and clarinet in the Wycliffe Gordon Jazz Orchestra alongside Aaron Diehl and Michael Dease; and on the Harry Allen Orchestra's With Roses (Triangle7, 2023), a big-band vocal date arranged and produced by Harry Allen that also features Grant Stewart, trombonist John Allred, and trumpeter Warren Vache. Both brothers, jointly credited as "Peter R. Anderson" and "Will R. Anderson" on reeds, are heard on Boardwalk Empire Volume 1: Music from the HBO Original Series (Elektra, 2011) with Vince Giordano and the Nighthawks, which won the 2012 Grammy Award for Best Compilation Soundtrack for Visual Media; earlier sideman credits from their Juilliard years include Sharel Cassity's Just for You (2008) and Thomas Barber's Janus Bloc featuring Jimmy Cobb's Snow Road (2009), the latter attributed to Peter individually.

The duo's most recent studio album, The Best of Berlin (Arbors Records, 2025, ARCD19494), is a 13-track program devoted entirely to Irving Berlin, with Peter, on tenor saxophone and clarinet, arranging every number; it followed Peter and Will Anderson Featuring Jimmy Cobb (Outside In Music, 2020), recorded July 23, 2018, at Trading 8's Studios in Paramus, New Jersey, with pianist Jeb Patton, bassist David Wong, and the drummer Jimmy Cobb, the last surviving member of the Miles Davis rhythm section on Kind of Blue, released within days of Cobb's death in May 2020. The brothers have appeared on screen in HBO's Boardwalk Empire and Mildred Pierce, in the film Revolutionary Road, and in the documentary Vince Giordano: There's a Future in the Past; they were selected by Jazz at Lincoln Center in 2016 to perform in a concert honoring clarinetist Benny Goodman, and they appeared repeatedly on Garrison Keillor's A Prairie Home Companion, closing out their final appearance in 2016 with a duo reading of "Lotus Blossom" for Billy Strayhorn's centennial. Their ensemble has performed in more than 35 U.S. states and toured Japan, and both brothers remain active as teaching artists through Juilliard's Nord Anglia program, having lectured and given clinics at more than 100 schools and universities.

The New York Times called the brothers "virtuosos on both clarinet and saxophone," and that dual command, treble reed and low reed, swing-era clarinet and postwar tenor sax, is the foundation of Peter's musical identity as distinct from Will's: where Will's voice centers on alto saxophone and flute, Peter's centers on tenor saxophone and clarinet, a division audible on nearly every joint recording from Correspondence (2012) onward. His stylistic vocabulary was built directly from his Juilliard mentors, baritone giant Joe Temperley and the Basie-band tenor of Frank Wess among them, and from direct contact with veterans including Bob Wilber, Jimmy Heath, and Benny Golson; the working group's repertoire runs from 1920s and 1930s dance-band and Tin Pan Alley material (Artie Shaw, Benny Goodman, Irving Berlin) through swing-era small-group jazz and into hard bop, reflected in the "Hard Bop" and "Bop" style tags Discogs applies to Deja Vu, Blues for Joe, and Clarinet Summit. Peter is also the group's primary arranger of record, credited with writing every chart on The Best of Berlin (2025), and the brothers' original compositions on Deja Vu (2015) and elsewhere extend that same repertoire-conscious, chart-driven approach to newly written material rather than only revivalist repertory.