UPDATE!! : late in the day on Thursday, May 4th, Jay-Z was added as festival headliner. Austin City Limits Music Festival has announced its massive lineup for two weekends of festivities. The event will deliver more than 140 bands across eight stages at Zilker Park, October 6-8 and October 13-15. Headliners are Jay-Z, Red Hot Chili Peppers, Chance the Rapper, The Killers, Gorillaz, Martin Garrix, and The XX.