What I’ve actually done is set up my p121 as controller for my sx. I mainly use piano for r/h voice.
I have sx to the side of my p121, ( ie L shape, I can’t play them stacked) fortunately with my setup I can see the sx screen and I can press some of the buttons, but I use the registrations and the pedal to get me thru the variations and fills for a particular song.
rikkisbears,
I do not want to convince you to buy, I just use your case to explain how the software works and its capabilities. And how they solve problems in the real world.
---------
Groovyband Live! (GBL) supports up to 3 midi input devices for notes input.
You have 2 (your arranger: 61 synth action keys; and your piano: 88 hammer action keys). How can you use them effectively?
GBL supports 3 types of voices:
1) Acmp voices (8 parts): driven by the sequencer for style playing.
2) Lead voices (4 parts): played maually. On Yamaha arrangers these are known as L/R1÷3. In GBL they can simulate that and do much more.
3) Aux voices (4 parts): played manually AND assigned to a second/third keyboard/pedalboard.
Aux voices are customised/saved with each style and travel with it. When you load a style the Aux voices are set up automatically to match the given style.
Aux voices can be used to embellish a performance: having always ready 4 parts to play on a second/third keyboard/pedalborad IN ADDTION to the (OTS) lead voices, can be handy.
Aux voices can be configured as layers/split or any combination in between, because for each of the 4 parts you set:
1) Where you want to play it (2nd or 3rd keyboard/pedalboard)
2) The min/max note range.
3) The min/max velocity range.
Lead voices can be configured as you like from L1÷3/R to R1÷4 (and all the combinations in between). Every OTS (you have 8 for each style) can establish a different partitioning. You can assign an OTS to every main, not necessarily in the canonical order 1->8. OTS (and MAINS) can be reordered at the push of a button. The link between an OTS and a MAIN is preserved even when reordering them.
You have an independent harmony function (fully configurable) for each of the 4 Lead parts (and saved with the OTS).
If you set R1÷4 to play different instruments, each one playing different harmonized note(s), you have an effective way to play quartets of instruments as in a real orchestra (complex multi timbral chords).
As usual all possible combinations are possible, the limit is only your imagination. Not the tool, anymore!
rikkisbear could decide to use the arranger keyboard for chord recognition and lead voice play. And use the piano keyboard for aux voices (possibly using only one, a piano for example!).
Or it could decide the other way around: arranger play on the piano, aux voices on the synth action.
No matter what: the sounds of both keyboards will be correctly configured each time you switch a style.
P.S.: A performance, among the other things, stores the position of the split point, and optionally can refer to a NULL (empty) style.
The empty style NEVER plays any accompaniment part: its only pourpose is to establish the split point and chord recognition machinery so that you can drive your OTSes (and possibly their harmony functions) as a conventional synth 4 parts wide performance.
By loading a single registration (whose number is unlimited) you load a bank of 8 performances (each one 4 parts wide) + global 4 parts wide aux voices (driven by the 2nd/3rd keyboard).
With the software we supply 3440 unique OTSes in all musical genres (good sounding and perfectly balanced). You can use them without any tweaking for instant gratification. Or as building blocks/starting point for your own customisations.
We have also a "smart split" mode, on by default. For those interested, more in depth explanation
here. There are many ways to use our software. Probably calling it only "realtime arranger" is reductive .....
P.P.S: Have you noticed that we have a comprehensive, up-to-date
user manual written in clear and plain english, for those willing to master the subject?