Metcalfe's unique style is a result of his extensive experience in classical, pop and electronica. As violist with the Duke Quartet he released many CDs and toured worldwide. Metcalfe’s string arrangements played by the Dukes feature on many albums by pop artists including Morrissey, Simple Minds, The Pretenders, Coldplay and Blur.
Metcalfe was instrumental in the formation of the record label Factory Classical, an offshoot of Tony Wilson's Factory Records. He also wrote arrangements for various popular artists, including Morrissey, Simple Minds and The Pretenders. He released an album of his own, The Inner Line, to positive reviews. In 2004, another album, Scorching Bay, was released, followed by "A Darker Sunset" in 2008. 'The Appearance of Colour' was released on April 2013 as part of Bowers and Wilkins Society of Sound subscription series.
Commissions include a set of pieces for the guitarist Tom Kerstens and an album of electronic/acoustic music for 'cellist Matthew Barley. His music has also been used by various contemporary dance companies.
He also collaborated with Peter Gabriel, writing arrangements for his "song-swap" album, Scratch My Back, and for the tour following it. For New Blood (2011), which he co-produced with Gabriel, he arranged and orchestrated versions of Gabriel's songs.
In 2015, Metcalfe released a solo album titled The Appearance of Colour on Real World.