I know this is late but there is a Montrose Music festival covering all sorts of stuff.
And for future note The Links Hotel has a fortnighly folk club with a good range of guests. Search for the hotel or simply Montrose Folk Club.
There is the Abbey folk club in Arbroath and sessions in the Three Bellies Brae pub in Kirriemuir on some night or other.
Going north there is the Stonehaven folk club which is very friendly and has a festival with a Water Celeidh held in the open air pool!!!!