Widespread Panic holds the record for most concerts at Red Rocks Amphitheatre with a dazzling 36, and all but one were sold out. The venerable Southern jam band will return to the venue tonight through Sunday to tack on three more. The band is celebrating its 25th anniversary with a 23-date cruise through mostly Western cities following a headlining set at the massive Bonnaroo festival in Manchester, Tenn., earlier this month. As expected, all three nights are long since sold out, but tickets always have a way of turning up. Doors are at 5 p.m. tonight and Saturday, 4 p.m. on Sunday. Try your luck outside the parking lots.