I don't know a lot about Ayr ( known for "Honest Men and Bonny Lasses" - Tam o'shanter - Rabbie Burns but you are on the edge of Galloway where I grew up and is missed a bit by the tourists.Countryside - Wonderful hills and rivers. Great bits of unblemished coast ( if you can avoid the livestock grazing on the beach).
Recommended - Kirkcudbright lovely wee fishing town you may have heard of because there was a fishing boat lost not so long ago. Creetown - Interesting Gem Museum Castle Douglas - Small market town, Threave castle was the home of the Black Douglases There are also Stranraer and Wigtown on the coast below Ayr Dumfries - which was stong connections with Robert the Bruce and Burns. Wanlochhead is the highest village in Scotland and there is a lead minning museum. Above Ayr you are heading towards Glasgow with its museums and shops and the start of the West Coast Island such as Arran.
Not so sure about the music as I was quite young when we left but I did notice that there were lots of festivals. I suggest that you need a big Guide book and go to the tourist information as soon as you get there. Other people, will have many other ideas.
I will be passing through Dumfries on my way back from Shetland in the summer but I can only stay one night. Have fun
Julie