Is the thing that bugs you the most, Donny, seeing the music, or just the 'heads down' attitude?
I've seen PLENTY of non-reading keyboard players do that!
I really like the trend towards big color screens on the arranger itself, where sheet music, cheat sheets or just lyrics can be displayed. The thing is, these are being displayed in an area where the audience EXPECT you to look (at least from time to time) so you don't get quite the same reaction as to a 'bookworm'.
So far (due to my G70's OS) I only use it for the occasional lyric, but if I were doing a jazz gig, or a gig that involved a LOT of requests, having a cheat sheet display would be a life saver, and avoid the flipping through fake books between songs, etc., that seems to bug you.
The on-screen displays seem to offer the best compromise between the necessity of sheet music on some types of gigs (remember, SOME gigs require a vast repertoire of unrehearsed tunes) and the appearance (at least to the audience) that you are not reading from a fake book. Even a MusicPad Pro has to stick up and look like some kind of 'book'...
Certainly, learning your core repertoire as quickly as possible is part of the skills a pro should have, but off the cuff requests, or songs you may not have performed for a few years, what is better? To use the display, or either not do the tune at all, or clam it up badly?
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An arranger is just a tool. What matters is what you build with it..!