Looking for something different to do this evening? Well, the elusive ambient/downtempo collective Atmospheric Audio Chair has reformed — this time with promotional support from Apple and Wired — and will be holding a post-work (5-8 pm) monthly session on the 33rd floor of Chicago's W Hotel Lakeshore. Led by DJs Ken Waagner and Tom Pazen, enjoy a healthy dose of relaxed music in the only local bar that rotates 360 degrees every hour. Also happening tonight is the third installment of XOJK at Sonotheque, which proudly features John Herndon of Tortoise and Lazy FM's Rob Hamilton. Both events are 21+ with no cover.