Silent Disco on the Vistula stairs where good sounds will take care of: Lodołamacz Serc and Sosia. Lodołamacz Serc is a Warsaw DJ specializing in hits of 90 and 00. Sosia is a DJ incarnation of the singer Sonia Wąsowska. As a DJ she likes to play a cross-section of girl music from the 80s to the present. She loves guilty pleasure hits, horror movies, still watches lots of cartoons and is crazy about her cat.