I don't think there is a shop in C# house any more, hasn't been for years. Hobgoblin last ran the shop there, then they moved to Rathbone place.

It might be worth the trip to Camden for specialist Irish music - there used to be a scruffy shop in a road just off Parkway that had some really arcane stuff that you'd be very lucky to find elsewhere.

Hobgoblin and the big stores in Oxford Street are the best bet and they're all close to each other.

Anahata