Flamenco is the national song and dance of Spain. It originated hundreds of years ago (the exact date of flamenco as we know it today is disputed...maybe in the 1500 or 1600s? with influences from even earlier on...) in Andalusia, Spain. Andalusia is the largest region in Spain - encompassing most of the southern portion of the country.
Flamenco music usually has a singer, guitar player, dancers, and "hand-clappers." The hand-clappers are really what make flamenco unique (in my opinion), because they clap off-beat. When I studied abroad in Granada, Spain, flamenco was seen everywhere since Granada is in Andalusia. I even went with my university group to see a flamenco show in the white caves of Granada! It doesn't get any more authentic than that :)
Check out a video of some flamenco music/dancers in Spain:
Did you notice the off-beat clapping?
Anyways, I went to the show, "Carmen," and really enjoyed it. The theater was pretty small - maybe 200 people, and I was lucky to sit in the fourth row. The performers were fantastic, and the live music was great as well. If you ever find yourself in Spain, seeing a flamenco show is a must!