Regret there are no regular sessions in Sidmouth.
No Festival either in 2005.
There will be a Middle Bar Singers Reunion in The Anchor in the Spring though.
That apart, nearest sessions/ folk club are at The Globe, Topsham on Sundays. Contact Pete Hargrave.
You might also try The Red Lion, Sidbury on 1st Sunday of the month though I'm not sure myself if this is still happening.
Suggest you contact Eddie Upton at Folk South West for details of other sessions in East devon.
Hope this is helpful.