He spent much of his time at school writing songs and it was only a few weeks before going to King's College, Cambridge to read English that he attended an Arvon Foundation course in West Yorkshire.
While at Cambridge he joined the Footlights where his contemporaries included fellow King's student David Baddiel who later invited him to contribute music to The Mary Whitehouse Experience on BBC radio.
On leaving Cambridge, he wrote and composed music for the award winning Radio Four series And Now In Colour but was soon invited to meet Alan Ayckbourn in Scarborough and commissioned to write a play for the studio at the Stephen Joseph Theatre.
His play Calendar Girls, adapted by Firth from his own film, found favour with audiences across Britain during its 2008/09 tour.
In the process it broke the all-time British box-office record for a play and also continued to sell out during its months in the West End.
In 2004, Firth released a solo album, Harmless Flirting, completing a tour of words and music with fellow playwright Willy Russell that won positive reviews at the Edinburgh Festival.