You can try expanding the bars such that each bar is in effect one half of a full bar. Set the Tempo to twice what it originally was.

Then, what used to be a quarter note beat is now an 8th note beat, in effect.

This works better with some styles than with others.

OR, as Noel points out, you can roll your own MIDI bass part using either Note-Entry methods or Recording MIDI from keyboard or other MIDI instrument controller.


--Mac