Reggaeton is a a type of Latin American dance music (not in that it is electronica, but I would consider it more closely related to techno than rap). It has a very strong backbeat, is rather repetitive, and the singers tend towards high energy rather than technical skill. Most of it is sung in Spanish, although you find English and English/Spanish mixes.
Reggaeton (AKA Reggaetón or Reguetón) first appeared in the late 1990s. It was a mix of bomba and plena, hip hop and rap, and some reggae. (The reggae influence doesn't make much of a mark on the music, but the basic beat is said to have originated in the Shabba Ranks song Dem Bow). Reggaeton lives primarily in Puerto Rico and the Dominican Republic, but has been spreading outwards since it's inception. I first heard it in Cape Verde (where I was told it was Batida music from Angola), and it's well known in America's Latino populations.
Reggaeton's 'official' dance is perreo. I haven't seen it, but I hear it has "sexually explicit overtones". I imagine that there is more to it than that, but that's enough to be getting on with.
If you are interested in hearing some, my favorite is Gasolina by Daddy Yankee. It's easy to find on-line (that is to say, download illegally), and sounds exactly the same as all the others, except better.
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