J Mascis Share definition Flag The worlds greatest guitarist. Frontman of the largley influential rock group Dinosaur Jr. Has other side projects such as J Mascis and The Fog and Broken Mascis scene. You may be good,but you're no J Mascis. J Mascis by jerjemy July 4, 2006 0 0 Get merch Get the J Mascis mug. Buy Now — $32.95 See more merch
