Having heard the programme myself, I can vouch for its excellence - and not a theatre organ to be heard throughout the whole programme, for those who fail to appreciate such instruments' inherent awesomeness
- another will soon be aired as there was far too much interview to cram in to one episode.
OT already but have you ever heard any old the old 1920s recordings of the big Willis? This is Harry Goss-Custard playing Lemmens' Storm Fantasia in 1927: http://www.youtube.com/watch?v=zaCaUMm4OyA
I don't know exactly what's changed about the organ but one thing's for certain - in 1927 all that had been built was the Lady Chapel, chancel, Eastern transepts and crossing and a whacking great brick wall across what is now the archway into the "Central Space". The organ had to be voiced rather speculatively: for me, it has a raw power and aggression (particularly with the Pedal reeds - listen to that 32ft ROAR at 3:06!) that's now tempered rather by a more spacious (though perhaps not much more reverberant) acoustic. Personally, I'd like to see it regain that bite with some more aggressive, French-style reeds in the Central Space or on the nave bridge... and it could do with a big nave organ (for which they presently use a Makin, the Willis being simply too far away)! Perhaps THAT's what could be done with the now-unplayable and long-disused 4/75 Willis III currently in Sheffield City Hall...