Despite an ambivalent reception by contemporary music critics, Dark Magus inspired noise rock acts of the late 1970s and experimental funk artists of the 1980s.

According to Magnet magazine's Bryan Bierman, "the hip, 'with it' kids [sat] side-by-side with middle-aged tuxedoed couples, expecting to hear 'My Funny Valentine.

[3] Lawrence was a highly regarded young saxophonist at the time, while Gaumont was enlisted by Davis in response to incumbent guitarist Reggie Lucas's demand for a pay raise.

[8] Davis eschewed his previous performances' keyboardists in favor of a three-guitar lineup of Reggie Lucas, Dominique Gaumont, and Pete Cosey, who had a penchant for guitar wails and pedal effects.

[9] Davis often stopped the band with hand signals and created longer empty spaces than traditional jazz breaks, encouraging the soloists to fill them with exaggerated cadenzas.

Christgau attributed the album's jazz input to Lawrence's "Coltranesque" saxophone, and the rock elements to guitarists Lucas and Gaumont, who "wah-riff[ed] the rhythm", and Pete Cosey, who produced "his own wah-wah-inflected noise into the arena-rock stratosphere.

"[11] In The Rough Guide to Rock (2003), Ben Smith described the music as "an amazingly dense amalgam of free jazz and funk",[12] while Fred Kaplan from New York magazine called it "electric jazz-rock fusion.

"[10] The cover image is, as The New York Public Library blogger Shawn Donohue describes, "an enigma" as "it is hard to make out anything more than shapes and colors, possibly Davis in tripped out profile on the far right.

"[26] David Keenan placed it on his all-time 105 best albums list for the Sunday Herald and said by ornamenting heavy grooves with tribal percussive instruments, wah-wah effects, and otherworldly trumpet bursts, Davis had instinctively fused the most advanced elements of modern African-American music.

He contended that the group improvisation on tracks such as "Wili" foreshadowed the drum 'n' bass genre: "Miles was invoking the primordial powers of the electronic urban jungle.

"[11] In The Penguin Guide to Jazz (1998), Richard Cook and Brian Morton wrote that each performance comprises only "shadings and sanations of sound, and as one gets to know these recordings better one becomes almost fixated on the tiniest inflexions.

[22] Just when you think the shit can't get much higher, Miles comes in and hits the wah-wah down hard on the horn and the next thing you know, you're slappin' five to the man upstairs ... By the rite of Dark Magus, I can fake the cool in no time flat.

In The Rolling Stone Album Guide (2004), J. D. Considine wrote that Dark Magus expressed the band's surging rhythms better than In Concert and offered a balance between their affinity for improvisation amidst their desire to rock.

[30] Jeff McCord of The Austin Chronicle found the performances impassioned, enduring, and highlighted by effectively competitive playing between each duo of saxophonists and guitarists.

[19] AllMusic's Thom Jurek called it an exaggerated and excessive showcase of Davis' disoriented psyche and felt that, although the rhythm section is historically captivating, the other musicians' playing is inconsistent, albeit enthraling.