The most interesting pieces from So You Think You Can Dance - and usually, the most popular - all follow the same piece wise structure, like a pop song does (quiet beginning, add instruments, catchy verse, loud hook and end).
For hip hop:
Beginning: Allude to storyline, usually a guy and girl in love.
Middle: Break out from the introduction of the story/characters with a series of complex movements in synchronization.
Next: Do a series of individual complex movements and/or duet stunts.
End: Resolve the story with some sort of "quip" ending alluding back to the characters here.
Beginning: Allude to storyline
Middle*: Separate out to do your own thing, then allude back to the story line in a count
Next*: Break out stunts
End: Resolve with no resolution, alluding back to the storyline.
*The two starred steps may intertwine...and this is far less structured than the hip hop pieces, but there's definitely a pattern to it.
Example: (And don't get me wrong, I think this is brilliant anyway):