ummm, well its bloody awesome for dance music because you dont really have to worry about finding what song goes well with others, or more, you get a much more defined group of songs that you can narrow down even further. I label all my songs with the key and its fucking uncanny how gd it works man. All my mixes on soundcloud are harmonic. I also use the bpm counter on it to label my songs to make beatmatching quicker, enabling me to create better mixes. Once you learn to mix harmonically, its like a whole other level man. Im not sure how it would go with hip hop and that tbh.