Adding real-time CV changes to an existing pattern

Is it possible/easy to add (by over-dubbing) CV variations in real-time (from an external MIDI controller) to an existing ER-101/102 pattern? e.g. you have a pattern with CV note data and gates already recorded and you want to add modulation data to the 2nd CV by moving a controller knob in real time.

Yes. That would be the alter record mode. Here is a brief video giving a taste of the workflow:

This video covers all 3 recording modes: real-time, alter, and step. If you skip to 3mins into the video, you can watch just the alter record mode.

Wow…thanks Brian for that instant response!