I was wondering if anyone could tell me what the other song buttons do, as far as I can see they all do the exact same thing!

Actually, you can set the buttons to pull up song lists from different directories. You can also use them to pull up styles from the disk.
For example, you set button 1 to pull up the songs in, let's say, your HipHop directory on your hard drive. You select the directory by using the PopUp button to take you to the hard drive. The select the directory and hit "next". The keyboard will ask if you want to change to this directory and you say yes.
Then, select song button 2. You can use the same procedure to select songs from, say, Country and Hillbilly directory, or whatever you have created on your hard drive. Repeat the procedure for all the buttons, if you have that many directories with songs in them.
I haven't tried it, but supposedly you can use the buttons to save style lists in the same manner.
Of course, this is all assuming you have a hard drive! Otherwise, I suppose, the buttons will all be alike.
Hope this helps.
DonM