OFF THE GRID

What does this year’s CMJ have in common with those of recent years? The best parties are the unofficial ones. Today, none are better than Exploding in Sound Records’s Unofficial Birthday Party Spectacular, the afternoon-into-late-night event featuring 11 bands, four of which we can confirm are really good. Headliners Speedy Ortiz, for instance, are riding on the much deserved acclaim that followed their recent album, Major Arcana (acclaim that their earlier “Sports” EP deserved as well). Pile and Porches will appeal to fans of local bands like Titus Andronicus and Parquet Courts, and Ovlov is best heard at a house show in suburban New England, but, here in New York, Silent Barn is close enough. The other seven are probably great, too, but there’s only one way to find out.

Sat., Oct. 19, 3 p.m., 2013