Thank you for the replies!
I have a few hundred midi files from building websites back in the 90s, but those don't work with the "lesson" modes (timing, waiting, etc.) that the DGX series digital pianos have. The piano will just play them, and allow me to change the tempo/pause, etc. I have only found those that are are on the internal memory, and those from Yamaha that came on a disk with the keyboard will actually work with the lessons.
Will the midis from this site work with those lesson modes, given that it is geared directly at the Yamaha digital pianos? I will gladly contribute to this site.
Thank you again!