I'm a little late on this but I really like Songbook on the Korg. I'd like to see Yamaha implement the features of Songbook via the MFD feature. Not sure why they haven't seems like it's a software thing that shouldn't be that difficult to implement, but there may be more to it than meets the eye. I do like and use Yamaha registrations in conjunction with the MFD feature and it does the job I need it to do.