As documented in the user manual (chapter MIDI connection), you can control the CP4 by another MIDI controller.
Connect MIDI OUT of the external controller to the MIDI IN port of the CP4.

All the notes (and other MIDI events) coming from the external controller will play one of the part of the current performance on the CP 4, depending on the MIDI channel used by the external controller for the transmission:
ch 1 --> MAIN part
ch 2 --> LAYER part
ch 3 --> SPLIT part

More details of what you can do with the external controller (for instance, change the current performance or send control change messages like volume or expression) are in the MIDI appendix of the reference manual.

Double check the MIDI settings in the Utility / MIDI menu if something doesn't work.

Hope this helps.

Pino, Italy

Hi Pino,

Thanks for you reply!

I think the thing I was getting at was whether or not those parts can be played separately. I now that when using the CP4 keyboard, MAIN and LAYER play together and SPLIT is separate. But if I have, say, another controller going into ch 2, will it play _only_ the LAYER part or will it be combined with the MAIN part the way it is when I use the CP4 keyboard?

Cheers from Canada!

Ben

Sorry for the delay, I wasn't able to login....
well, yes, you can play the parts indipendently.

Any performance is the collection of 3 voices (or sounds).
The main part is always playing, the other no: depends iof the part (layer or split) has been enabled.

If you keep "off" the other parts, you'll play with the CP4 only the MAIN part, but if you send via MIDI the notes from another controller to the channel 2 or 3, the sounds / voices defined in the curren performance will play (respectively: thje LAYER voice if you send notes on MIDI channel 2, the SPLIT voice when using channel 3.

Hope I was enough clear. My suggestion: "try it"

Ciao

Yes, here is an odd way to trick the CP4 into being able to play two different CP4 sounds from two different keyboards. Though, it only works when you assign a sound to the Main and a different sound to the Split. For instance, say you want to reserve MAIN for strictly Piano (and have all 88 Keys available) and you only want to play an organ sound from an external keyboard.

Once you assign the Piano sound to MAIN and assign the Organ sound to SPLIT, hold down the SPLIT button press the very bottom note on the keyboard (A0). Now, the keyboard is virtually Split with the Piano sound accessible to the upper split (full 88-note keyboard) and the organ sound assigned to the lower Split which is ONLY accessible from the external keyboard transmitting on Midi Channel 3. You can even change the sounds on the CP4 of the lower split from the external Midi controller without changing the sound of the upper split.

Remember to save this performance setup in a New Performance location.

With reference to the last post above "Now, the keyboard is virtually Split with the Piano sound accessible to the upper split (full 88-note keyboard) and the organ sound assigned to the lower Split which is ONLY accessible from the external keyboard transmitting on Midi Channel 3."

I use that procedure to assign the CP4 Standard Drum Kit, which has superior, great drum sounds (or any other CP4 drum kit) to the Split part and use various MIDI tracks I created from Cubasis in my iPad to play the CP4 drum kit (MIDI in to the Split part on MIDI Channel 3), and then play a piano voice in the MAIN part over the entire keyboard and an additional voice (such as strings or brass) in the Layer part that I sweep in and out via a foot controller pedal assigned to volume in just the Layer part. For a drums/percussion play along track this sounds far superior than playing an audio drum track from Cubasis (or any other audio source) into the CP4 via the Aux In port. However, sometimes an adjustment has to be made in Cubasis to have the same drum in the Cubasis track play the same drum in the CP4 kit (i.e. a bass drum in Cubasis playing a bass drum in the CP4). However, for my just playing along purposes, the specific drums that are played without adjustment work well.