I think it’s pretty safe to assume that many of the concert-goers in attendance at the Lindsey Sterling/Evanescence concert at Ruoff Home Mortgage Music Center had never heard of Cellogram before that night. And it’s also pretty safe to assume they won’t forget them, either. The unusual, two-person act was fascinating to watch and delightful to listen to. Consisting of cellist Dave Eggar and percussionist Chuck Palmer, the duo engaged the audience with their enthusiasm and antics. Their set included a lively mix of classical, rock, folk, tribal, bluegrass, and jazz that was just about perfect for a balmy evening under the stars.