Sidechaining has been around for years; this is the process of using one signal to control another. A couple classic examples are using a kick drum to gate a bass part, or doing de-essing - isolating the high sibilant frequencies from a vocal, and using those to trigger compression so that the sibilants come down in volume.
Lovely article. If only you could explain the same principle to Nuendo users. I know the principle is the same but I need step by step guidance with pictures. I could play all positions of a mixolydian b7 scale and run minor 9ths add 13 arpeggios but music technology is too much for me! (maybe less playing and more manuals?). In any case, thank you for the article!