Please help – struggling with midi

What’s the simplist way to convert a multi-track midi recording into 88 discreet note on/off switches for a piano simulating patch? I can do the second part, but how do i run and split the midi data?

Essentially I just don’t understand the "sorry I only take single track files" message on the seq object when I open a midi sequence of, say, a bach piano piece…

Kind wishes

Lee Morgan