Hi Gar: As one who also owns & plays an 88 note acoustic piano (Steinway Grand) as well, I for one believe 'arranger mode' playing requires only 61 keys, and rarely necessitates using the octave +/- buttons either.

Auto accomp mode simply put, requires an entirely different playing approach than solo piano/keyboard. Solo playing necessitates more keyboard real estate (additional octaves) for left-hand arpegios, octave strides, bass lines, etc. In contrast, with auto accomp mode performance, the auto accomp rhythm section (specifically auto accomp bass part) provides that, with the LH's job to trigger the chords, plus rhythmic comping and/or (smooth) chord transition changes. In split keyboard mode, with the split point set at F#2, I find 1-1/2 octaves quite sufficient to handle this task, leaving 3-1/2 octaves (G2-C6) available for everything played with my RH. Hey, this is only a 1/2 octave less than available on an 88 note piano above middle "C".

The only time I need more keys is for traditional 'solo piano' style playing. For 'some' piano works, even a 76 note keyboard isn't sufficient. For those situations when I want to play solo piano style, I simply midi my Roland A-33 76 note controller to my T2, giving me the flexibility of only having to drag along a longer 76 note board when required, while enjoying the benefit of transporting a more compact 61 keyboard the rest of the time..

Scott