alt Hacker NewsA long hold of one note doesn't mean there isn't harmonic progression. It just means the progression is slow in that part of the song. It's often done to create a massive contrast that occurs when the progression finally...progresses. In electronic music, this often comes as the drop or some similar kind of break.
No, in electronic music harmonic progressions are done by manipulating timbre.
Try it yourself - play one note on repeat and start twirling the cutoff knob.