He went into music production in the early 1980s; in October 1980, he co-produced and engineered the debut self-titled album by Australian rock band INXS.

[6][14][15] McFarlane described the Questions' first three singles with Parkinson as "minor psychedelic pop classics": "Sally Go Round the Roses" (July 1967), "And Things Unsaid" (October) and "Something Wonderful" (February 1968).

[6] That group also won the New South Wales state final of the Hoadley's Battle of the Sounds, and finished third nationally: behind the Groove and the Masters Apprentices.

[6] In September 1970 McGuire was a founding member of a progressive rock band King Harvest, with Leo de Castro on lead vocals and lead guitar (ex-Leo and the Browns, Leo and Friends); Jimmy Doyle on guitar (Silhouettes, Aesop's Fables, Moonstone); Mark Kennedy on drums (Spectrum); and Steve Yates on keyboards (ex-Rush, Expression).

[17] They performed cover versions of contemporary hits, including Jimmy Webb's "Wichita Lineman" and The Rolling Stones' "Jumping Jack Flash", which appeared as singles in 1971 on Festival Records.

[17] He rejoined Parkinson for a few months before teaming with de Castro in Friends, another progressive rock group, by December that year.

[17][18] Also in Friends were Kennedy, with Charlie Tumahai on vocals and percussion (Aesop's Fables, Healing Force, Chain) and Tim Martin on saxophone and flute.

[18] By April that year Friends line up of McGuire, de Castro, Kennedy and Burton on guitar, had recorded versions of "Lady Montego" and "Freedom Train" for the Various Artists' album, Garrison the Final Blow Unit I (June 1973).

[19] In October they recruited Col Loughnan on saxophone, flute, vocals, and piano (the Crescents, the Delltones, Kala) and by December they issued their debut single, "Rock'n'Roll Fight (Going On)", on Mushroom Records.

[21] Tony Catterall of The Canberra Times caught their performance in October 1975 as they previewed material for a subsequent album, which "showed an improvement" over their previous work and noted that "McGuire's bass was always rock-solid but ready to fly at a moment's notice".

[24] As a member Windchase, McGuire helped to finish their debut album, Symphinity, which was issued in June; however he had already left before it appeared.

[24] From 1977 to 1980 McGuire joined Parkinson and Kennedy in the Southern Star Band which also had Tommy Emmanuel on guitar and Frank Esler-Smith on keyboards.

[25] In the late 1970s, McGuire turned to production work, he was the mixer, engineer and co-producer of INXS, the debut album by the Australian rock band of the same name, which was released on 13 October 1980.