I'm new here so... hi there!
Before I start ask about OP-1 I would like to share with you some thing (maybe it will be useful for someone).
It's a pattern for the endless sequencer. It's very easy to use and completely analog (you need a printer, a paper and a pen). It's a staff divided into 50 parts per line so you can easily pen musical notes (also as letters), rests or sustained notes and easily enter it into the endless sequencer. I've read that a lot of people want to save their sequences - it can resolve this problem.
I hope it will be useful.
PS I downloaded this music sheet - I added only numbers 1-50.