Happy hardcore is a genre of music typified by a very fast tempo (usually around 160–180 BPM), often coupled with solo vocals and sentimental lyrics. Its characteristically 4/4 beat "happy" sound distinguishes it from most other forms of breakbeat hardcore, which tend to be "darker". In its original incarnation, it was often characterized by piano riffs, synthetic stabs and spacey effects. This genre of music is closely related to the typically Dutch genre of Gabber. Happy hardcore evolved from rave music around 1991–1993, as the original house music-based rave became faster and began to include breakbeats, evolving into breakbeat hardcore.