It could have been bedlam — three days of nonstop music on eight stages with occasional downpours — but the 75,000 fans who flocked each day to the Austin City Limits Music Festival in Zilker Park last weekend were a mellow lot. That was reflected in the peace signs, headbands and crochet attire, as well as the abundant enthusiasm for a recycling program that rewarded can collectors with free ACL T-shirts and left nary a Budweiser or bit of trash in sight. Music lovers were rewarded with a buffet of 100 performances ranging from headliners Neil Young & Crazy Horse and Red Hot Chili Peppers to gospel to indie rock. De rigueur in Austin, which has a proud reputation for being “weird,” can mean anything. That is, as long as it’s not overdone.