Okay so since nobody really explained it to you yet. I will...On your MPC you have your mode button you can then go to your program. When you are in the sample screen you notice how it always has 4 spots for each sample....when you assign a sample you automatically take spot one. well you can put up to four sounds on one pad. So you take a couple of different kicks and you put them together to make a new sound. Same thing with hats or percussion of any sort. So you then have a layered sound. Hope that clears it up.