The Sheffield Sessions festival at Easter is another all-sessions event.

Out of the formal festivals I find Sidmouth is best. Over time the different session pubs have specialised in different forms of music, so you know exactly where to go to play English music, or Irish music, or chorus song.

On the other hand I've never had much success finding suitable sessions at Whitby, where although there are established session venues the type of music being played seems to depend on whoever got their first, and I have spent a lot of time wandering round town, often without success.