A "drop" is a feature in a lot of electronic dance music where the beat builds , changing in rhythm, and climaxes with a slight pause and then some kind of rhythmic payoff - if that makes any sense.

I'm not really a fan of that kind of thing, but I'm still intrigued, and fairly excited to hear it. And anyway, I'm sure there'll be other things on the album to enjoy - seems there's going to be decent variety.