The album was named the eighth best of 1986 by rock critic Robert Christgau, while jazz writer Ian Carr said it epitomized the electric guitar's range as an instrument.

[7] His compositions on the album included a blues piece called "Black Bottom", the berceuse "Broken Toys", "Devils Doll Baby"—which featured Sharrock's frenzied slide guitar playing—and "Princess Sonata", a suite showcasing a range of techniques.

[5] Reviewing for The Village Voice in September of that year, Robert Christgau found Sharrock's avant-garde jazz playing "funky and beautiful" but also daring sonically.

"[8] At the end of 1986, Christgau named it the year's eighth best record in his list for the Pazz & Jop critics poll,[12] and later wrote that both Guitar and Sharrock's next album—Seize the Rainbow (1987)—could restore any listener's interest in jazz fusion.

[7] Jazz critic John Fordham said the album was a "sensational, terrifying exercise in abstract sounds, fragmented blues, feedback and slide-guitar splinterings," but also "one of the most effective antidotes to the prim and studiedly dramatic conventional jazz-guitar performances on the circuit" at the time.

[6] In The Rough Guide to Jazz (2004), Ian Carr felt Guitar epitomized the breadth of the electric instrument, "ranging from impressionistic sound poetry to abstract-expressionist blitzkrieg".