Happy Birthday. Sonic Boom Records Capitol Hill, 1525 Melrose Ave., 568-BOOM. 3 p.m. Free. All ages. When Sub Pop signed Happy Birthday last year, the Vermont trio was less than a year old and hadn’t even recorded any songs. They’ve since started earning their keep, last month releasing their self-titled debut album. Happy Birthday’s first single, “Girls FM,” is bouncy with a strong Pixies-circa-Surfer-Rosa feel, thanks to the ragged guitar, drummer Ruth Garbus’ sweet and airy vocals, and the humming sing-song chorus. That happy, head-bobbing vibe characterizes the rest of the record, along with front man Kyle Thomas’ extra-nasally voice, his blithe and breezy melodies, and some flat-out rad guitar solos. ERIN K. THOMPSON