Surprise! The theme for this year's Unsound Festival in Krakow is meant to pull the rug out from beneath our collective expectations of the festival experience.

Some artists are pre-announced, others not; you won't know who they are until they're up on stage. And many will perform in unexpected places or unusual combinations. The aim is to play with preconceptions about festival formats, live performance, and the very idea of going out to see music.

Certain events are completely shrouded in mystery, such as a unique night held in Wieliczka Salt Mine's ballroom, buried deep underground. It's one of several surprising new venues this year, along with a project in Krakow’s best known public space – the medieval Main Square – where musicians will respond to the Hejnał, a tune played by a trumpeter each hour from St Mary’s Church.

This year’s program also focuses on collaborations, some pre-announced, others not. There are even shows where just one side of the collaboration will be revealed beforehand, while drummer Greg Fox participates in a Gregidency where he’ll be joined by musicians neither he nor the audience knows about in advance!

So check your expectations at the door — because unexpected pleasures are the best kind.