Bassnectar is exactly that — a sweet distillation of low-frequency pollens, collected from the flowers of many sizes and colors. And just like the name implies, the crystalline sugar that results from all that busy-bee gathering is always the king of the show. Seeing DJ Lorin Ashton’s black mane thrashing behind the mixing board, or the blinding light installation that serves as his backdrop, is great, but it’s the chest-shaking, face-melting bass that brought Red Rocks to capacity and kept everyone moving (or forcibly vibrating) during the more-than- three-hour set.