Three years ago, local indie-rock act Sleepy Eye Giant was operating as an experimental duo with Wil York handling guitar and vocals and Lucas Rhoad pulling double duty on the drums and keyboards. The two met while attending Erskine College in the upstate town of Due West before relocating to Charleston. In 2010, York and Rhoad added keyboardist Tami Boyce to the lineup. This summer, they’ve expanded things even more with the addition of second guitarist Brad Butler. “Although Brad is short in stature, he fits in fine,” York says. “It’s been super fun with the addition of keys and another guitar — a bigger, fuller sound. We look forward to recording a bunch of new material soon.” Sleepy Eye Giant recently returned from a hot and steamy road trip (no A/C in the van) through Florida. The foursome will share the cozy stage at the Royal American (970 Morrison Drive) with songwriter Ryan Sheffield at 9 p.m. on Thursday.