Javelin, with Weekend. Vera Project, 305 Harrison St., 956-8372. 7:30 p.m. $8. All ages. Brooklyn duo Javelin cobbles together boomboxes, broken synths, and pop-culture effluvia into a captivating and intensely fun approach to postmodern electronic music that perversely combines discofied funk and fractured hip-hop to gently swaying global-pop melodies and Bacharach-ian arrangements. It’s dizzying and discombobulating, but by stacking layers upon layers of goofiness upon their grooves, Javelin delivers a richly rewarding sonic experience that, in concert, transforms into a participatory experience. This may be the only show this week where you’re asked to BYOB (Bring Your Own Boombox). JASON FERGUSON