Tickets are available at ravinia.org.
High demand for ticket caused delays on the Ravinia website when tickets went on sale at 5 a.m.
"Some people said it was taking them three and four hours to get through, and we have our IT department looking into it," said Ravinia Director of Communications Nick Pullia.
Ravinia Festival's 2012 season includes 120 events from June 7 to Sept. 9, featuring classical, chamber music, rock, R&B, jazz, country, dance, world, kids concerts and the summer residency of the Chicago Symphony Orchestra.
Concerts include Seal; Esperanza Spalding; Al Green; Yo-Yo Ma; Sarah McLachlan; Kiri Te Kanawa; Macy Gray; Mat Kearney; Nathan Gunn; Anita Baker; Demi Lovato; Itzhak Perlman; Glen Campbell; Roger Hodgson; The Knights; Gavin DeGraw; Diana Krall; Idina Menzel; Boz Scaggs; Jaap van Zweden; Duran Duran; Sergio Mendes; Joshua Bell; Natalie Merchant; Patti LuPone; Earth, Wind & Fire; Juilliard String Quartet; Colbie Caillat; Patricia Racette; Jimmy Cliff; Philip Glass; Andy Grammer; Dawn UpShaw; Daryl Hall and John Oates; Jake Shimabukuro and more.
"Santana sold almost immediately," said Pullia. "Colbie Caillat and Gavin DeGraw sold out. Train is sold out. James Taylor, both nights are sold out. So some of the heavy-hitting shows that you'd expect are already gone."
In-person sales begin on May 19. Phone sales do not begin until May 20.
For a full schedule of events, please visit ravinia.org. Phone sales begin on May 20 at 847-266-5100. A $7 service fee is added to all ticket orders.