I am aware that you can play prerecorded wave file on the CP4 and output the sound alongside the sounds from the keyboard. I also know that you can edit and change the file names with the keyboard but this is a quite a laborious process. Can you change the file names using a computer directly to the USB stick instead?
You can change the name of any .wav file with your computer, as long as you are aware that changing the .wav extension is not allowed and you do not change the seventh and eighth characters of .wav files generated on the CP4 Stage itself.
As per page 35 of your Owner's Manual:
Important
Audio files created by your stage piano will have “}{” as their seventh and eight characters. Recorded audio is quieter than that produced by the keyboard, and these characters tell the instrument to increase the playback volume in order to maintain a suitable balance. Accordingly, these characters should not be removed.
Thanks for your help. I haven't purchased a CP4 yet but making a few final checks before I do.