Early reports from beta testers and videos from cuckoo have suggested that you can use the OP-Z entirely without a screen. For those coming from the OP-1, it might be hard to believe that this would be possible. I’m happy to report that the rumors are true, the entire experience of making music on the OP-Z is self-contained and my personal opinion is it’s even better that way.
What’s the big deal
The comparison to the OP-1 and it’s beautiful screen (which was well ahead of it’s time!) is not really a fair one. The tape based method for recording and ease of recording notes in directly meant that you need a lot of visual feedback to know where you are, where the loop point are, and to do delicate operations like splitting tracks, copying and deleting to try again.
On the OP-Z, with it’s emphasis on sequencing and patterns, you need substantially lower resolution into what you’re doing. There’s a well defined, albeit constrained, workflow that works wonderfully and provides just enough visual feedback to know where you are and what you’re doing. That’s why things as simple as say a monome’s grid of lighted pads can be all the interface you need.
Speaking of lighted pads, I find the LED feedback on all the buttons to be well thought out and mostly intuitive. Paging through encoder parameters with the lights changing to different colors is one small example that you might not even notice after awhile because it just feels right. Key combinations (i.e track + shift + some button) start to build up muscle memory and I find the need to reference the guide goes down quickly (although I understand the complaints about the sparse manual).
What do you need the screen for anyway
The iOS app does offer some non-essential perks. Seeing which synth engine you are using for example can be nice since you can better anticipate what the parameters and sounds could be. It’s also nice for looking at the current values of things like an LFO, but you also get a good amount of feedback from the LEDs like the pulsing of the LED as an indicator of the LFO modulation speed.
Finally the visualization sequencing of the OP-Z can only be done by connecting to the app. While it’s fun for a bit, I don’t find myself drawn to do that every time I use the OP-Z so it’s moreso a thing I play with once in awhile.
Overall I think Teenage Engineering made a well thought out interface and workflow which really doesn’t need any screen at creating music. The iOS app augments certain aspects of the setup, but is more of a bonus.