Best things to do in Tallinn in 24 hours??

Hey guys, for sudden and annoying visa reasons I need to leave Finland for a day, So I'm going to Tallinn, I went once before but it was high summer and I don''t think I really saw everything the place has to offer. I'm into indie music/ typical hipster stuff, art, culture but also tradition (Also food reccomendations, casual good food) and all that so any recommendations would be brilliant!

Kiitos in advance.

-Luke

Edit: Thanks for the advice everyone, had a great time, had been in 2009 but the city has changed a lot since then, I honestly think It's got more going than Helsinki, great people, great food and drink, great hospitality.