Exporting audio in Logic 9 to match a new tempo

Logic 9 has a function to export the tempo data of a song (including beatmapping tempo data) into the audiofiles which then enables matching to another session. Select the files in the original song arrange page and go to options/Tempo/ export tempo to audio file. This then allows the follow tempo function when you import them into another session. I am guessing that your original drum tracks were not recorded using 9 as I believe that with new 9 recordings the export tempo function is not a required step as it is printed to the audio file already. The exported tempo data includes any speed changes on the original if beat mapped or tracked to a varying tempo. These will be removed if you import to a fixed tempo song. I am not in front of logic right now so am explaining this from memory so hope this solves your problem. Good luck.

This then allows the follow tempo function when you import them into another session.

I think if you try the procedure you just described, you'll discover that it doesn't work. If you record audio in project A, and then import that audio into project B, Follow Tempo will not be enabled. Regardless of whether or not you use the "export tempo to audio file' command, and regardless of which version of Logic you're using.

There are some other approaches to enabling Follow Tempo, but this particular approach doesn't work.

I forgot Flex needs to be enabled you are right follow tempo is not.

Just checked on a session I have where I beat mapped a kit recorded over 16 tracks and removed the tempo changes by exporting the tempo to audio files and then changing to a fixed tempo. If I import those files to a new session with a different tempo map and enable flex the performance conformes to the new map. I Use slicing and group the drums to keep it phase coherent.

If I import those files to a new session with a different tempo map and enable flex the performance conformes to the new map.

Yes, and this is true with any audio. It doesn't matter where those files came from. Flex will Flex them. If Flex is on, the audio will conform to whatever tempo map is currently in effect.

Follow Tempo and Flex are related, but they aren't the same thing. Sometimes Logic is fussy about making Follow Tempo available. There are various rules that apply. But usually I can get around this and accomplish what I want just by turning on Flex.