"...onyt agoraf y drws..." (English: "...unless I open the door...") is an orchestral piece lasting approximately 15 minutes by the Welsh composer Guto Puw.
It was first performed on 9 August 2007, at the Proms by the BBC National Orchestra of Wales, conducted by David Atherton.
[2] Each of the three doors in Penfro was represented by an instrument (trumpet, clarinet, violin) in a box in the Royal Albert Hall.
The Daily Telegraph's critic described it as a "succession of vivid tableaux" and "liked the way it mixed pictorialism with broader expressions of mood and emotional states".
However, the critic added that the "spatial games played with the Albert Hall didn't amount to much, and the piece overall lacks weight", whilst commenting that Puw was a composer "well worth noting".