Real-sounding instruments of those instruments you hear in live bands. Drums, bass, acoustic guitar, electric guitar, steel guitar, mandolin, banjo, fiddle, strings, piano, organ, accordion, harmonica, congas. Even it were only a dozen, it would be acceptable. I mean dead on, not a pretty good rendition.

A multi-track recorder, so that you don't need a DAW of any sort. Could plug in guitars, etc.

A screen 8.5" wide that scrolls in sync with the song.

Totally wireless, no cords at all.

In lieu of the above, a PA built into the stand. Put the arranger on the stand, start playing.

Storage for unlimited lead sheets. Press a button and transpose the lead sheet to a new key.

A separate screen that flips out on each side of the arranger for your bandmates to view the lead sheet in real time.

Buttons that you could trigger just by looking at them. Even better than that, mind-recognition technology so that when you think ADD STRINGS, it does it.

Ask me in about a week, my Audya should be here in about an hour.