Together with guitarists Jerry Garcia and Bob Weir, drummers Bill Kreutzmann and Mickey Hart, and keyboards player Ron ‘Pigpen’ McKernan, bass player Phil Lesh was a founding member of The Grateful Dead. During 30 years of performing and recording with The Dead, he was largely responsible for introducing them to jazz improvisation through his interest in the work of John Coltrane and Miles Davis, as well as the electronic and modern classical music composition that he had studied (along with Steve Reich) at Oakland’s Mills College under the tutelage of Italian composer Luciano Berio.

From the almost garage rock stance they had adopted under their first name The Warlocks in 1965, The Dead’s sound gradually shifted into extended jam versions of such standards and popular hits as Noah Lewis’s “Viola Lee Blues”, Wilson Pickett’s “In The Midnight Hour” and Martha And The Vandellas’ “Dancing In The Street”. These elongated bouts of improvisation were realised during the 1965–66 Acid Tests period, where writer Ken Kesey and his troupe of Merry Pranksters (along with ‘Acid King’ chemist Owsley Stanley) staged happenings at various venues to advocate the free use of LSD which, at the time, was still legal. Documented by author Tom Wolfe in The Electric Kool Aid Acid Test (1968), Kesey’s Acid Test soirees were his attempt to achieve a form of shared psychedelic transcendence by imbibing shots of LSD-laced Kool Aid, with house group The Grateful Dead supplying the perfectly attuned accompanying soundtrack.

For his part, however, Lesh soon became more interested in learning how to take the group’s music higher through more natural means. After he was induced to play the instrument by Garcia (Lesh had studied violin and then trumpet at college), he began to explore his own bass guitar playing technique within The Dead by working on a signature sound that displayed his own musical interests, as well as providing a solid rhythmic structure for the rest of the group to take off from.

In his autobiography Searching For The Sound (2005), he explains how he developed his style in order to steer the group in a more experimental direction: “My approach to the bass had solidified fairly quickly. I soon reached a saturation point with the prevalent style of bass playing, which was to stick to the root and always play on the downbeat. I wanted to play in a way that heightened the beats by omission, by playing around them, in a way that added harmonic motion to the somewhat static chord progressions of the songs we were playing then. I wanted to play in a way that moved mechanically but much more slowly than the lead melodies sung by the vocalists or played on guitar or keyboard.”

Lesh’s approach encouraged the other members to open up and let loose, while still maintaining a semi-disciplined sense of order that prevented the songs from tumbling into complete chaos. One fine example of this combined energy can be heard on a recording of a concert at San Francisco’s Avalon Ballroom on 12 October 1968. Here, his thundering bass refrain provides the sonorous undertow that booms through their version of Blind Gary Davis’s classic gospel blues lament “Death Don’t Have No Mercy”, as well as being the anchor that holds firm a particularly high-flying rendition of The Dead’s signature cosmic composition “Dark Star”. The set concludes with a freeform feedback freakout, a rolling surge of amplified guitar noise and drone that again hints at Lesh’s contemporary music influence and his desire to break free from the limitations of any accepted musical convention.

By way of introducing modern composition into the mix, Lesh recruited his old music student room mate Tom Constanten to play on The Dead’s second studio album Anthem Of The Sun (1968). As well as playing keyboards, Constanten contributed an electronic tape and prepared piano piece called “Electronic Study #3” (aka “We Leave The Castle”) to the four-part “That’s It For The Other One” suite that opens the record. Constanten’s more abstract addition to the group’s already hallucinogenic sound spun it into another dimension and, although his presence within The Dead was short-lived, the electronic music seed he had helped to plant took root and resurfaced in another form further down the road.

Another electronic composer championed by Lesh was musician and computer scientist Ned Lagin, who he teamed up with to record Seastones. Described by Lagin as “electronic cybernetic biomusic”, it was recorded in stereo quadraphonic sound with contributions from Garcia and vocalists David Crosby, David Freiberg and Grace Slick, and eventually released on the Dead’s Round Records subsidiary label in 1975. During some of The Dead’s 1974 concerts, Lesh and Lagin played segments of Seastones as a separate section, with Lesh’s bass accompanying Lagin’s combined digital synthesizer and mini-computer set-up, and Bill Kreutzmann occasionally adding his cosmic drumming.

In 1983 The Grateful Dead set up their non-profit organisation The Rex Foundation (named after their late road manager Donald Rex Jackson who died in a car crash) from money raised at their benefit concerts. Over several years Lesh was responsible for discreetly releasing $100,000 of the Foundation’s funds to support various composers and musicians whose work he felt was neglected and needed to be heard by a larger audience. Those who benefitted from these grants included such overlooked UK composers as Bernard Stevens (1916–1983), Havergal Brian (1876–1972), Robert Simpson (1921–1997), Harrison Birtwistle (1934–2022), Michael Finnissy (born 1946), James Dillon (born 1950) and US composer Elliott Carter (1908–2012).

Following the death of Jerry Garcia in 1995, the remaining members of The Grateful Dead decided to go their separate ways to recuperate. Three years later, Lesh went back on the road as part of an extended Dead splinter group called The Other Ones, joined by Weir, Hart and piano player Bruce Hornsby. Lesh eventually went on to reboot his Phil Lesh & Friends project, which he had originally formed in 1994 as an acoustic version of The Grateful Dead. Featuring a rotating line-up that included members of Phish, The Black Crowes, The Allman Brothers and Little Feat, Phil Lesh & Friends’ concerts consisted of harder, faster renditions of Dead compositions that retained the spirit of the band’s original psychedelic jam sessions. On a smaller scale he also played in a duo project with Weir called Furthur, as well as The Terrapin Family Band with his son Grahame.

Lesh went back on the road with the revived Grateful Dead in 2009, as well as the 2015 Fare Thee Well concert tour that marked the group’s 50th anniversary. Since then, due mostly to his various health issues, he preferred to abstain from later reunions. On 25 October 2024 at the age of 84, Phil Lesh died peacefully at his home in Marin County, California.