James Edward Pugh was born in Butler, Pennsylvania on November 12, 1950, started piano at five and trombone at ten, and had three teachers before he was twenty: William Hill from 1960, Matty Shiner from 1963, and Emory Remington at the Eastman School of Music from 1968. He also names a fourth, learned first from records and later from the next chair over: Urbie Green. Pugh was at Eastman from 1968 to 1972, where he played in an ensemble directed by Chuck Mangione, and his first appearance on record is a student one, the Eastman Trombone Choir album that Remington conducted for Mark Records in 1971.

He was twenty-two when Woody Herman hired him, and the four years that followed are the reason he is a jazz musician rather than a studio musician who once played jazz. Pugh joined the Young Thundering Herd in 1972 and stayed until 1976, through six albums and two Grammy Awards for Best Jazz Performance by a Big Band. On Giant Steps, cut at A&R Studios in New York on April 9, 11 and 12, 1973, he is one of three trombones behind a reed section holding Frank Tiberi, with Andy LaVerne on electric piano and Bill Stapleton writing most of the charts. By Thundering Herd, recorded at Fantasy Studios in Berkeley on January 2, 3 and 4, 1974, the credit reads "trombone, lead," and it stays that way through Herd At Montreux from the festival on July 6, 1974, Children Of Lima with the Houston Symphony Orchestra, and King Cobra, taped in January 1975. The last document of his time in the band is the largest: the 40th Anniversary Carnegie Hall Concert of November 20, 1976, a double album on RCA Victor with Joe Lovano and Tiberi on tenors, on which Pugh is the credited trombone soloist on four numbers, among them "Apple Honey" and "Crisis."

He left the road for a different band and then for no band at all. In 1977 and 1978 he was the tenor trombone in Return to Forever's brass section, on Musicmagic (Columbia, 1977) and the double live album Live (Columbia, 1978), where he also plays baritone horn, alongside Chick Corea, Stanley Clarke, Joe Farrell and Gayle Moran. Corea kept him for Secret Agent in 1978, on which he plays trombone on six of the nine tracks and bass trombone on one. Then he settled in New York and became something else entirely: the city's first-call freelance trombonist for three decades, with more than four thousand recording sessions to his name. He is the only recipient of the National Academy of Recording Arts and Sciences Virtuoso Award for Tenor Trombone, given after the New York recording community voted him tenor trombone MVP five years running. That career is real and it is enormous, and it is also the part of his biography that misleads: the standard list of names attached to him runs Yo-Yo Ma, Steely Dan, Paul Simon, Barbra Streisand, Tony Bennett, Michael Jackson, Madonna, Pink Floyd and Frank Sinatra, and tells a reader almost nothing about what he plays.

What he played, underneath all of that, was jazz, steadily, for forty years. The sideman line runs from Yusef Lateef's In A Temple Garden (CTI, 1979) and Jay Hoggard's Days Like These through Stanley Turrentine's Inflation (Elektra, 1980), Marvin Stamm's Stammpede (1983), Bob Mintzer's Urban Contours (1989) and the euphonium chair on the George Gruntz Concert Jazz Band's Blues 'N Dues Et Cetera, cut in New York in January 1991. In the 1990s it thickened: Jim Hall's Youkali (CTI, 1992), where Pugh is not only the trombonist but the arranger of the title track and "All Across The City" and did additional arranging on everything else; the Joe Roccisano Orchestra's two Landmark albums; David "Fathead" Newman's Ellington tribute (1994); Joe Lovano's Rush Hour (Blue Note, 1995), Gunther Schuller's project, on four tracks; Gerry Mulligan's brass-ensemble date Dragonfly (Telarc, 1995); Paquito D'Rivera's Portraits Of Cuba (Chesky, 1996); J.J. Johnson's The Brass Orchestra (Verve, 1996), nine of its fourteen pieces; and Don Sebesky's tributes to Bill Evans and to Duke Ellington. He has been in the Manhattan Jazz Orchestra's trombone section since 1989 and in the all-trombone group Super Trombone since 1995. Later came Carla Bley's Looking For America (WATT/ECM), taped at Avatar Studios on October 7 and 8, 2002, and Wayne Shorter's Alegría (Verve, 2003), on which he plays two pieces.

The longest of those associations is with John Scofield, and it spans fifteen years and three records. Pugh is on five of the ten tracks of Grace Under Pressure, recorded at the Power Station in December 1991. He is on This Meets That (EmArcy, 2007), the album whose horn writing Scofield built the record around. In between is the one many listeners outside jazz have actually heard: Up All Night (Verve, 2003), where Pugh plays trombone on tracks 1, 4, 6, 7, 8 and 11 in a four-piece section with Gary Smulyan on baritone saxophone, Craig Handy on tenor, flute and bass clarinet, and Earl Gardner on trumpet, arranged by Scofield himself. The band cut the record at Long View Farm Studios in West Brookfield, Massachusetts in December 2002, with Avi Bortnick on rhythm guitar, samples and loops, Andy Hess on bass and Adam Deitch on drums. The horns went in separately at The Hit Factory in New York the following January and were never in the room with the rhythm section.

His own records are few and deliberately unalike. Crystal Eyes (Pewter, 1984) was cut over two sessions in December 1981 and February 1982 with a New York studio cast that included Randy Brecker and Marvin Stamm on trumpets, Lou Marini on reeds and David Taylor on bass trombone. The Pugh-Taylor Project (DMP, 1985), recorded in 1984, pairs his tenor trombone with Taylor's bass trombone over strings, winds and a rhythm section that included Marc Johnson and pianist Bill Dobbins; a sequel, Pugh-Taylor II, followed thirty-three years later. He shares the billing on SteepleChase's Jam Session Volume 8, cut in September 1997 with Ryan Kisor and Jimmy Greene over Andy LaVerne, Jay Anderson and Billy Drummond, the same pianist he had sat behind in Woody Herman's band twenty-four years earlier. From 2002 he made four albums as the duo E'nJ with the Japanese trombonist Eijiro Nakagawa, and X Over Trombone (Albany, 2007) is the concerto album: his own Concerto for Trombone and Orchestra, Jeff Tyzik's, and the first recording of Nathaniel Shilkret's 1942 concerto for Tommy Dorsey, all with the Colorado Symphony Orchestra under Tyzik.

Composing has run alongside the playing throughout. "Lunch with Schrödinger's Cat" was premiered at Lincoln Center in 1989 by Marin Alsop and the Concordia Chamber Orchestra, of which Pugh was a founding member and principal trombone, as he was of Jonathan Sheffer's EOS Orchestra. His trombone concerto was premiered in May 1992 by the Williamsport Symphony and given its New York premiere in March 2000 by Joseph Alessi with Leonard Slatkin conducting the New York Philharmonic. He re-premiered the Shilkret concerto at Carnegie Hall in 2003 with Skitch Henderson and the New York Pops, and is a founding member of the Graham Ashton Brass Ensemble, which recorded a whole album of his and Daniel Schnyder's music for Signum. His themes and arrangements have run on National Public Radio and, since 2009, on the Tony Awards broadcast. He taught at New York University, the University of the Arts in Philadelphia and SUNY Purchase before joining the University of Illinois at Urbana-Champaign in 2005 as Distinguished Professor of Jazz Trombone, a post he now holds as Professor Emeritus of Jazz Performance. He founded the University of Illinois Jazz Trombone Ensemble in the autumn of 2006; it won the International Trombone Association's Kai Winding Jazz Trombone Ensemble Competition in 2012 and again in 2017, and his students and groups have taken American Trombone Workshop awards six times. He has been the solo trombonist with Steely Dan since 2000, on Two Against Nature and Everything Must Go and on the road, and he is still on new records: Dave Stryker's Stryker With Strings Goes To The Movies, cut in early 2024, has him as the solo trombone voice on one track.

Pugh is a lead player who solos, which is a rarer thing than a soloist who can play lead, and the order matters: Woody Herman put him at the top of a trombone section at twenty-two and left him there for four years, and everything since has been built on the sound and the accuracy that job demands. The tone comes from Emory Remington's studio at Eastman, the singing legato approach that produced most of the American orchestral trombonists of the second half of the century, crossed with Urbie Green, whose lightness and small-bore clarity Pugh learned first from records and later from the adjacent chair. What made him employable everywhere was the doubling: he is credited across his catalog on tenor trombone, bass trombone, alto trombone, euphonium and baritone horn, sometimes three of them on one album, so a contractor could hire one player for a section chair that changed instrument between cues. He has been closely involved in the instruments themselves, helping develop small-bore horns for both the Edwards and S.E. Shires companies and prompting David Monette's TS6 and TS11 tenor trombone mouthpieces. The recognition that fits him best is the one the recording business gave him rather than the jazz press: the National Academy of Recording Arts and Sciences named him its Virtuoso Award winner for tenor trombone, and no one else has ever received it. All About Jazz files him, correctly, under jazz trombone.