BOONE, N.C. — Gregory D. Guay, son of Lisa and Jeff Pengel of Durham, Maine, and Dan Guay of Greene, Maine, has completed his master’s degree in master of music: classical guitar performance at Appalachian State University. Gregory achieved a GPA of 3.9. While attending ASU, Gregory worked as an adjunct professor of guitar at Emory & Henry College, Va., and also as a graduate teaching assistant at ASU. Gregory is also certified in Suzuki Guitar Instruction and taught 5- to 10-year-olds at the Montessori School of Mt. Pleasant, S.C., and private lessons for grades K-12 at the Charleston Academy of Music, S.C.