Grateful Dead book 3rd show at Horizon

Tickets for a third Grateful Dead show at the Rosemont Horizon,6920 N. Mannheim, Rosemont, will go on sale at 10 a.m. today. Thenew show will be at 7:30 p.m. April 15. The other shows, on April 13and 14, are almost sold out. Tickets are $17.50 and $18.50.Tickets will go on sale at 2 p.m. today for Pink Floyd (without RogerWaters), who will play the Horizon at 9 p.m. May 21 and 8 p.m. May22. No other dates will be added. Tickets are $25. Tickets forboth both shows are available only at Ticketmaster outlets(559-1212). Tickets will go on sale today for the Gregg Allman Band and John Kayand Steppenwolf performing at 8 p.m. May 19 at the Holiday StarTheatre. Tickets are $17 and …