..a lower patch...a mid range patch...a high pass on the synth...to create a stereo pad drone patch...plan to improvise on top of this pad with my guitar
So it looks like "Overdub" is what you want to do, yes?
Basic Example:
*Record first signal on Track1.
*Place Track1 in playback.
*Record second signal on Track2.
*Place Track2 in playback.
*Repeat on Tracks 3&4 for remaining parts.
*Send Tracks to the Main L/R Bus
*Play back Tracks using Track faders to blend/balance.
OR
*Send signals on Tracks to the Submix Bus.
*Send the Submix Bus to the Main L/R Bus.
*Play back Tracks, using Track faders to blend/balance and Submix Bus fader to set overall level.
If source is stereo, use the stereo tracks instead.