Hey Greg,
My friend and i will be in Krakow from Saturday to Monday, if you would like hanging out after Muse concert will be cool.
What i know is that there is going to be a Polish music festival on Saturday also, which last until morning Sunday (Wianki - Święto Muzyki 2019).
This is my second time in Krakow, last time i went for Krakow pub Crawl it is an interesting experience to meet new people and see several Krakow clubs.
eagle_eye i see there going to be a music band allusinlove from Castleford as a support band but no idea what is the schedule.
Cheers