The guitar can cross musical boundaries like no other instrument, its shape-shifting qualities conveying it instantly, from biting twang to gentle iridescence. A guitar quartet performing Australian contemporary works may seem one-dimensional on paper, but this is a truly thrilling and beautiful album. It helps, of course, that Guitar Trek’s skill and musicianship on each of their myriad instruments is staggering—Nigel Westlake’s cinematic 6 Fish shimmers on the group’s steel-stringed instruments, while Richard Charlton’s Guitar Quartet No. 8 “Five Tails in Cold Blood” inspires ensemble work of mesmerizing precision with fizzing, jazz-inspired licks. Phillip Houghton’s kaleidoscopic, emotive Opals explores every inch of the guitars’ musical potential. Ending the album, Elena Kats-Chernin’s “Bleached Memories” pays a lighthearted, ragtime homage to the guitar’s Baroque heritage.