So another advanced DJ tool is mixing in key, you can actually purchase a program called the mixing key. And what it does is analyzes your song and analyzes the musical key was produced in and it will assign it a candlelight key. And what that does is it just matches your library of songs and tells you which songs are compatible to mix in key with each other. You can also do it on record box because record box analyzes the musical key its maiden and then on your USB, you can actually sort by key and mix songs that are the same key together. This is an advanced tool that many big DJs like to use. It just really makes up for a nice clean mix because none of your bass lines or sins or musical elements are clashing when you're mixing