Old monophonic synthesizers have had all sorts of ways to sequence notes; from fairly complex programmable sequencers to simple arpeggiation. Arpeggiators are nice because they sequence the notes that are played on the keyboard in realtime, allowing the performer to improvise while taking advantage of the capabilities of the machine at the same time. Based on the speed of the LFO, the arpeggiator on the Sequential Circuits Pro-One will sequence all the notes in a chord in either ascending order, descending order, or both. Other synths offer a feature to play the notes in a random sequence. In this example the notes are played in ascending order. I cranked up the LFO and added some delay so that the notes blend into each other so you can hear the harmony in the sequence. With this technique you can sort of simulate polyphony on a mono-synth.

Analog Arpeggiation