I assume you are using Logic?
Can I assume you have a multi-instrument cabled into an audio instrument fader in Logic's environment?
This setup is described in the RMX instructional material.
With this setup you drag the midi files to the midi tracks of the multi instrument.
If you want to freeze it,
Put the audio instrument containing RMX in your arrange window.
Drag the midi files to the RMX audio instrument track.
Pile each part's midi file on top of each other and freeze that.
Be sure the audio instrument fader's channel parameter is set to "all"
yes i am using logic 7.01 in mac osx.3 on a powerbook g4.
i have the mulit setup fine...it works fine (i have 6 grooves going) however when i freeze that instance, the rest of the song plays back but not Stylus. when i unfreeze it.....it works.
i need to freeze it cuz ive maxed out my cpu usage.