I hate to beat a dead horse...........but I use music finder at every gig in conjunction with registrations. That doesn't mean that I'm linking them to regs because as we know that can't be done.

What I do is remove the factory MFD file that's something like 1500 plus entries. Many of the suggested entries for songs on the factory music finder I don't like I replace it with my custom MFD roughly 300 tunes and midi files. So now I've got a very manageable list and while I'm performing one song it's no problem to scroll to the next tune I'm going to play.

For singing I simply note either the key I'm going to sing the tune in or what works well is just enter -2, -1, +1, or + 2 etc. in the title entry in music finder. That's an easy reference that when I start the tune I need to hit the transpose button up or down. I also note in the title (thanks to Scott Yee for the suggestion) that I make notes for what instruments play on each OTS. So for instance an mfd entry look something like this:

Fly Me to Moon, -2, 1P2JG3S4Ham

Which would translate to hit transpose button down 2 steps OTS 1 Piano OTS 2 Jazz Guitar OTS3 Sax OTS 4 Hammond Organ . I also have a set of registrations for instrument voices easily accessible so that I can use those in place of the OTS settings. Many times I replace the OTS settings by revising the style. All my revised styles are saved to the hard drive in a folder scheme that mimics the on board folder scheme with the music finder on T4 and s910 it's simply one touch to the button "mf" that adds the file to music finder.

No it's not as good as Songbook on the Korg, but it's a very usuable system.