It’s all about entertainment from my point of view with that said I do use some SMFs and a couple of mp3s. They do the job when I need them to. One of the MP3s I use is for My Way. I recorded the mp3 backing track on my old Tyros using the style called Epic Ballad. There’s nothing like it on the Pa4x, so I use it as an mp3 on the Pa4x when I play that at a gig. Most of the time I do use styles and if there’s a decent piano where I play I’m sure to sit at the piano and play a few tunes, that’s insurance that I play for real and not just playing to backing tracks.