this is an interesting question - I've had a look at the realtracks and there appear to be several wma files for each style - each one cycles through some chord changes. It wouldn't be too difficult to work out the chord changes and produce the audio files required... but each one is accompanied by a file with the extension .bt0 - it's a compiled file so it's unreadable. These are presumably the instructions and pointers which enable the realtracks engine to use the associated wma...

Maybe this is something that pgmusic could supply us with? A realtrack maker? That we play into (following requisite chords etc) and it generates the mysterious but all important .bt0 file etc...

pgmusic must be using some kind of internal tools to be creating the realtracks in the first place. A user front-end on those tools.....muses...

Of course, it might not be part of pgmusic's plan to release the method of making real tracks...

Very interesting, though - I could do vocal realtracks for you guys!!!! (Some of you wince....)