It will come as no surprise to those who have encountered Tim Prottey-Jones' music - perhaps through his two albums voiced by the great and the good of the West End - that the strength of new rock musical After the Turn is its score. Prottey-Jones' songs are well written, with ambitious, rocky melodies and good use of lyrics.

The rest of Sarah Henley's production, however, is more of a mixed bag. Revolving around Michael (Liam Doyle), a young musician who has been traumatised into three years of silence by the death of his mother, are a cast of underwritten characters who occasionally slip towards caricature.

There are nice touches to the way that Michael's mutism is dealt with on stage, Stephen Rolley as Michael's younger self mirrors his actions and acts as his voice, but there is an inevitability to Doyle's own eventual number. His voice makes it worth the wait.

On the vocal front Steven Webb and Ashleigh Gray's performances as Michael's uncle and mother show off their West End calibre whilst Tori Allen-Martin delivers a confident and compelling performance as the romantic interest Lauren.

Most are seriously let down by the book though, which slips between explicit exposition and ill-motivated characterisation. Henley, who both writes and directs, struggles to capture or add insight to the mother and son dynamic which rings false and lacks naturalism.

Cast members all too readily resort to hitting tables or kicking things to display their anger. Only Greg Oliver as Wolf shows a hint of something more interesting as he flies into "rages".

The glimmer of a great show is present throughout After the Turn, it is just never given the chance to shine. The messy, aggressive design gives the piece good grounding and the four-strong band are ably led by musical director Tom Curran, who also uses the three backing vocalists to great effect throughout the score.

Seeing Prottey-Jones' music performed by this strong cast makes the show worth the visit, in spite of the piece's greater flaws.