The guitar is a powerful instrument, capable of shattering windows with a screeching metal solo or knocking over wedding cakes if it is thrown hard enough. Feel some musical muscle with today's Groupon: for $15 you get one general-admission ticket to see Red Horse on Friday, June 3, at the Avalon Theatre in Easton (a $30 value). The show starts at 8 p.m., but patrons are advised to arrive early, as most seating is general admission.

Red Horse is a folk-music supergroup comprised of independent artists Lucy Kaplansky, Eliza Gilkyson, and John Gorka. This trio takes the stage at the historic Avalon Theater to perform music from their eponymous album, as well as songs they have never recorded and some rearrangements of old classics. The group's music is chock-full of angelic vocals, enchanting instrumentation, powerful harmonies, and audible gum-chewing sounds.

Originally built as a movie theater in 1921, the 380-seat Avalon Theatre now hosts musical and dramatic theater, symphony orchestras, national musical acts, and screenings of classic films, along with smaller acts in the intimate Stoltz Listening Room. Although renovated multiple times, and even closing its doors from 1985 to 1987, this graceful art deco venue reemerged triumphantly to continue entertaining, with acts including The Wailers and Wynton Marsalis, and serving as an emergency landing pad for helicopters.