You can take a piece of audio with the right kind of swing, convert to midi in Logic, then use that as groove template so you can take other midi files and beats right on the beat will have the swing of the midi file extracted from the audio. you may need to add or take away some beats in the midi sequence or tweak it to your tastes. but i think the connection is a live one where you can alter the midi template and the rest will change during play back.
