Although Cambridge, Mass.' John Brown's Body has led the decade-long rise of the Northeastern roots reggae scene, the band has had a bumpy ride. In 2006, after five studio albums, the group lost bassist Scott Palmer to cancer and parted ways with both lead singer Kevin Kinsella and its blazing horn section. But the new album, Amplify, sees the band boosting its classic bass-heavy sound with hip-hop accents. The refreshed lineup also uses instruments like kora and cello to add dimension to its forward-looking take on the genre.