Music critics have acknowledged his development of an original approach that places him among the best-known blues harp players.

Paul Vaughn Butterfield[2] was born on December 17, 1942, in Chicago[2] and raised in the city's Hyde Park neighborhood.

Exposed to music at an early age, he studied classical flute with Walfrid Kujala, of the Chicago Symphony Orchestra.

[4] By the late 1950s, they were visiting blues clubs in Chicago, where musicians such as Muddy Waters, Howlin' Wolf, Little Walter, and Otis Rush encouraged them and occasionally let them sit in on jam sessions.

[8]Eventually, Butterfield, on vocals and harmonica, and Bishop, accompanying him on guitar, were offered a regular gig at Big John's, a folk club in the Old Town district on Chicago's near North Side.

[8] With this booking, they persuaded bassist Jerome Arnold and drummer Sam Lay (both from Howlin' Wolf's touring band) to form a group with them in 1963.

[9] During their engagement at Big John's, Butterfield met and occasionally sat in with guitarist Mike Bloomfield, who was also playing at the club.

These recordings also failed to satisfy Rothchild, but the group's appearances at the club brought them to the attention of the East Coast music community.

[6] Maria Muldaur, with her husband Geoff, who later toured and recorded with Butterfield, recalled the group's performance as stunning; it was the first time that many of the mostly folk-music fans had heard a high-powered electric blues combo.

With little rehearsal, Dylan performed a short, four-song set the next day with Bloomfield, Arnold, and Lay (along with Al Kooper and Barry Goldberg).

In England in November 1966, Butterfield recorded several songs with John Mayall & the Bluesbreakers, who had recently finished the album A Hard Road.

[9] The band added bassist Bugsy Maugh, drummer Phillip Wilson, and saxophonists David Sanborn and Gene Dinwiddie.

[9] In April 1969, Butterfield took part in a concert at Chicago's Auditorium Theater and a subsequent recording session organized by record producer Norman Dayron, featuring Muddy Waters backed by Otis Spann, Mike Bloomfield, Sam Lay, Donald "Duck" Dunn, and Buddy Miles.

By this time, the band included a four-piece horn section in what has been described as a "big-band Chicago blues with a jazz base".

[25] The album was recorded at Levon Helm's Woodstock studio with Garth Hudson and members of Waters's touring band.

[27] As a solo act with backing musicians, Butterfield continued to tour and recorded Put It in Your Ear in 1976 and North South in 1981, with strings, synthesizers, and funk arrangements.

[3] In 1986, he released his final studio album, The Legendary Paul Butterfield Rides Again, which was an attempt at a comeback with an updated rock sound.

[28] Aside from "rank[ing] among the most influential harp players in the Blues",[29] Butterfield has also been seen as pointing blues-based music in new, innovative directions.

[30] AllMusic critic Steve Huey commented, It's impossible to overestimate the importance of the doors Butterfield opened: before he came to prominence, white American musicians treated the blues with cautious respect, afraid of coming off as inauthentic.

[14] The induction biography commented that "the Butterfield Band converted the country-blues purists and turned on the Fillmore generation to the pleasures of Muddy Waters, Howlin' Wolf, Little Walter, Willie Dixon and Elmore James".

[14] In 2017, a documentary titled Horn from the Heart: the Paul Butterfield Story premiered at the Newport Beach Film Festival.

[31] Directed by John Anderson and produced by Sandra Warren,[32] it won the Outstanding Achievement Award in Filmmaking: Editing.

[36] Like many Chicago blues harp players, Butterfield approached the instrument like a horn, preferring single notes to chords, and used it for soloing.

There's a place called the Point in Hyde Park [Chicago], a promontory of land that sticks out into Lake Michigan, and I can remember him out there for hours playing.

[40] Writer and AllMusic founder Michael Erlewine, who knew Butterfield early in his recording career, described him as "always intense, somewhat remote, and even, on occasion, downright unfriendly".

[8] By 1971, Butterfield had purchased his first house, in rural Woodstock, New York, and began enjoying family life with his second wife, Kathy Peterson, and their infant son, Lee.

[7] Although strongly opposed to heroin as a bandleader, he developed an addiction to it, which, according to Steve Huey in AllMusic's Butterfield biography, led to "speculation that he was trying to ease his peritonitis symptoms".

The financial strain of supporting his drug habit was bankrupting him, and the deaths of his friend and one-time musical partner Mike Bloomfield, and manager Albert Grossman had shaken him.

An autopsy by the county coroner concluded that he was the victim of an accidental drug overdose, with "significant levels of morphine (heroin), ... codeine, the tranquilizer Librium and a trace of alcohol.