When it comes to writing concept albums, John Darnielle of indie-rock cult heroes the Mountain Goats once said, "I write songs, and they begin to sort of hang together, sort of like a crowd gathering in a public space." That's basically what happened with The Longing and the Short of It, a collection of older and newer songs from emerging composer-lyricist Daniel Mate. He realized that beyond their specifics — a man waits, frustrated, in an endless Starbucks queue; a boy feels he can never live up to his more talented brother; a woman runs into her ex in a public venue — the songs all dealt with longing, with an emotional or physical lack that needed to be filled. The world-premiere, cabaret-style production of these songs at Theatre at Arts Garage was simplicity personified, with the refreshingly Spartan musical direction (just an onstage piano) and set design putting our focus fully on the six actor/singers, who felt born to translate Mate's funny, knotty, and touching lyrics. If there was one showstopper among them, it was Elizabeth Dimon's uproarious "Starting Shit With You," which contained such brilliant lines as "Like a melted GI Joe, I'm sticking to my guns."