Ska punk is a fusion genre that mixes ska music and punk rock music together. Ska-core is a subgenre of ska punk that mixes ska with hardcore punk. Early ska punk mixed both 2 Tone and ska with hardcore punk. Ska punk tends to feature brass instruments, especially horns such as trumpets, trombones and woodwind instruments like saxophones, making the genre distinct from other forms of punk rock. It is closely tied to third wave ska which reached its zenith in the mid 1990s.