I'm a novice producer and recently, I have been tasked to do a dubstep or dnb remix of an electrohouse track. The first time i attempted a remix, the original artist send me a pack filled with loops and bass synth riffs. not knowing wtf to do, I figured to take the riffs, and cut up all the individual notes within, using an audio editor. then, i'd export all these little slices into a sampler in a DAW, and auto-detect each slice(now a sample) to properly match it's key. So, then I was able to engineer my own sounds to be in key with the original track's riffs, without actually using the old riffs in my remix. there's got to be a more efficient way to do this.