[IAmGraydon]

A 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.

[otabdeveloper4]

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.