I am using Real Tracks 1591. I have a full version of SampleTank and actually used a midi file of the song (Bad Bad Leroy Brown.....I know kinda goofy but I just wanted to do it anyway) The rest of the midi file piano could possibly be used but it didn't sound near as good as RT 1591. It would be cool if you could do like Real Drums and add points where you want an embellishment.