Aspen Snowmass will play host to a brand-new, music and mountain festival at the base of Buttermilk Mountain on Panda Peak, Apr. 5-7 with three days of music, spring skiing and riding and the celebration of Buttermilk closing weekend. The Après, promoted in collaboration with renowned music venue The Belly Up, will include live performances by Umphrey’s McGee on Friday, Apr. 5 followed by two nights of performances by The String Cheese Incident Saturday and Sunday Apr. 6-7.