Sounds like a piano/pad layer... you should be able to build a sound that plays exactly as you wish. Choose your favorite acoustic piano sound for the type of playing you are doing. Each of the Acoustic renderings in the CP4 Stage has a distinct quality of its own. You have the CFX, the CF3, and the S6.

You may first want explore the following sounds as starting points:

S6+Pad 1
CF+Pad
S6+Pad 2
CFX+Pad 1
CFX+Pad 2

I suggest even trying Piano layered with Choir...in addition to the many different Pad tones; what you're looking / listening for is a second sound that supports the piano without being at all *obvious*. It adds subtly to the sustaining portions of held notes without announcing what it is... so pay close attention to the balance between the Piano and the Pad behind it... less is more. Pay attention to, (and this will give you an advantage), the Reverb you use, and the amount you use on each... you'll find can make a huge difference to how something "feels" by the details in the Reverb. Differentiate Reverb Time, from the Send amount. Listen for the difference it's critical for how the spaces between what you play feel to the listener. Many people increase and decrease the SEND, but never play with the Reverb Time. Time gives the listener a sense of how big the room is. The Send tends to give the listener the sense of their distance from the instrument.

Treat the Pad sound like it's a thickening agent, that doesn't dominate the mix. It probably can get away with less Revetb, than the percussive Piano.

Create your own, don't concentrate on matching a You Tube video, (your CP4 Stage will sound way better than that...) study the Factory offerings. Then create your own.

Bad mister, thank you very kindly for your expert knowledgeable advise, I will try everything that you suggested . I'm really excited to learn that with some creativity the cp4 can be tweaked to sound a certain way that is very pleasing to the listener.
When I gain more experience I hope I will learn to become better at mixing/balancing the many sounds on the cp4 ,and adding the all important effects. I think some people are blessed with having a good ear for blending different tones while others have to work at it until they are happy with the results.
Once again, thank you so much for your help and for replying so quickly, I can't wait to start enjoying this fantastic keyboard.
Take care friend, Kevin

Hi Kevin, for that super-bright piano sound I'd probably start with one of the rock pianos, CFX Rock or CF Rock, tweak the EQ, and maybe put a compressor effect on it.

Have you checked out Bruno Zucchetti's customized Performances for the CP4? He demos some of them in this YouTube video https://www.youtube.com/watch?v=0bG6eikV9Z0, and gives a download link to his .C7A Performance file (free). Check out his Performance 037:RocknessCF (which uses the CF Rock piano) and Performance 038:RocknessCX (which uses CFX Rock piano). Might give you something to start with. Both of those use Slow Strings as the Layer. Maybe use something else, a Pad, instead (maybe 11:Atmosphere). Anyway, lots of fun stuff to mess around with there, and it's very educational to go through his edits and effects and figure out how he arrived at his sounds.

Hi M, Thank you so much for leaving a response , I'm very sorry that this morning I cannot leave a lengthy reply to you, we are just rushing to pack for a holiday. I will look forward to contacting you when we get home next weekend - we will not have a internet connection where we are staying!
Kind regards, Kevin

Hi m,
Thank you for your reply, I'm very grateful indeed for your help , I will certainly try out all of your suggestions . With the helpful advice that both you and Badmister have given to me, I now feel more confident that I will be able to find the sound that Iam looking for.
Yes, I have seen the Bruno Zucchetti performance video before, I'm pleased that you have reminded me about it,I have just downloaded the file ready to load to my cp4. As you mentioned, it will be informative to learn how he has done his edits and what effects have been used to achieve those super performances.It will also be great fun to play them!
Here is a link to a video that I found to be most helpful. https://youtu.be/kv4_0riJMnc By making adjustments to the parameters of the filter cut off frequency , the keyboard player demonstrates how he can dramatically alter the sound of a pad voice .He also makes some edits to the attack and release times.
I hope that from watching this video there will be other complete beginners like myself who will benefit from learning how to make this one easy tweak.
Take care friend, Kevin

Link to Youtube video below ,also a seperate URL
https://youtu.be/kv4_0riJMnc

Thanks. I like those pad edits.