Guy was born in Hampshire in 1991, and received his early musical training on saxophone and as a chorister in the Winchester Cathedral Choir. He studied at the Guildhall School of Music and Drama with Christian Forshaw, Nick Moss, Mick Foster and John Harle, also completing a masters degree with scholarships from the Countess of Munster Trust and the Guildhall. During this time he was selected as a finalist in the Worshipful Company of Needlemakers Woodwind Prize.

As well as performing with Kaleidoscope, Guy is often called upon as a multi-instrumentalist, performing on saxophone, clarinet, flute and oboe in pit bands, folk and rock groups, and as a session and orchestral musician. Theatre work has included engagements at the National Theatre, in the west end and on UK tours, with recent shows including Aladdin, Fun Home, Gypsy, Chitty Chitty Bang Bang, and Thoroughly Modern Millie. His versatility has also led to work with a wide range of groups and artists including Britten Sinfonia, Paul Weller, Icebreaker, Public Service Broadcasting, The Magnetic North, Afrik Bawantu and renowned ceilidh band Tribe of Tinkers.

Guy is a visiting woodwind tutor at Northwood College in north west London, and has many years experience delivering outreach sessions with Kaleidoscope for groups such as Live Music Now and the Worshipful Company of Musicians.