Pop tunes that burrow into your brain are called earworms. Owl City’s platinum-selling ditty “Fireflies” is a glowworm, pulsing rhythmically in your cranium along an endless electromagnet algorithm. “Fireflies” is a friendly worm, dwelling in your brain like a good guest, never being irksome or making a mess in your frontal lobe. Owl City (aka Adam Young) has taken a lot of criticism for sounding remarkably like Death Cab vocalist Ben Gibbard’s now-on-hiatus outfit The Postal Service. Well, so what. Taken on its own terms, Owl City’s oeuvre isn’t bad for a 23-year-old recently liberated from his mom’s basement in frosty Minnesota. If sometimes his kiddie-piano approach is a little too simplistic (“Hello Seattle”) or lacking in focus (his new single “Vanilla Twilight,” whose video features a bunch of people — including Shaquille O’Neal — staring at the sky), it’s still good pop. And the fact that it helps adolescent music nerds around the world believe there’s a future beyond the basement, well, that’s just an extra little hospitality gift.