The three-day festival, which began in 2006, features artists such as Hot Chip, Vampire Weekend, Iceage, Feist, Big K.R.I.T., Dirty Projectors, Beach House, Ty Segall and more.
The festival, which includes three stages, runs from Friday until Sunday. Tickets are sold out.
The festival also includes a "Book Fort," record fair, poster show, and craft coterie with unique and local arts and crafts for sale.
Friday: 3pm to 10pm. Saturday and Sunday: Noon to 10pm.
Will Call opens at 1 pm on Friday, July 13th, and 11 am on Saturday and Sunday, July 14th and 15th.
Union Park is located at Ashland and Lake on Chicago's Near West Side. CTA Green and Pink line trains stop at that intersection.
Friday: A$AP Rocky, Willis Earl Beal, Big K.R.I.T., Clams Casino, Dirty Projectors, Feist, Tim Hecker, Japandroids, Lower Dens, The Olivia Tremor Control, Outer Minds, Purity Ring
Saturday: The Atlas Moth, Atlas Sound, Danny Brown, Chromatics, Cloud Nothings, Cults, Flying Lotus, Godspeed You! Black Emperor, Grimes, Hot Chip, Nicolas Jaar, Liturgy, Lotus Plaza, Schoolboy Q, The Psychic Paramount, Sleigh Bells, Wild Flag, Youth Lagoon
Sunday: AraabMuzik, Beach House, Chavez, Dirty Beaches, The Field, Iceage, Kendrick Lamar, A Lull, King Krule, The Men, Milk Music, Oneohtronix Point Never, Real Estate, Thee Oh Sees, Ty Segall, Unknown Mortal Orchestra, Vampire Weekend
More info at http://pitchfork.com/festivals/chicago/2012/