A style of the Rock genre, Ska is a precursor to Reggae. It is characterized by heavy, walking bass lines, offbeat rhythm signatures. It is a fusion of Calypso, American Jazz, and R&B. In the 1990s, ska was fused with punk and became what most people recognize as ska. Ska punk is a less distorted, more Caribbean version of punk, and utilizes a bass section along with the traditional guitars and drums. The tone is upbeat, high energy, and fast paced. Vocals are melodic, but in the fusion with punk, the sing/scream vocal style is also popular.