I tested the Surface Pro 3 with the Pioneer DDJSX & Serato DJ...I used this setup for a few hours and the performance seemed to be solid (even with a USB hub). This could be a viable DJ solution, if it can survive a "live environment"
Download the Rap Beats App on your Android phone to record your lyrics over quality rap beats.
The free version has 3 beats and you can earn credits to download more beats by inviting your friends.
Upgrade to the professional version for $3.99 and get unlimited downloads!