Noel96 is correct but your case may be the same as mine when I recently attempted to revive some old recordings done with my late brother. Stereo MP3's are all that exist now. I also had some other tracks that were made with midi backing tracks in the same situation of existing only in mp3 format. My last post "This Time" is an example where I added piano, steel guitar and backing vocals to the existing stereo mp3. The process will be the same regardless if your mp3 is stereo or mono because you will be adding to the existing mp3, not modifying it. It is not the same if you still have the midi file. That would be much more ideal and easier plus yield a far better backing track. You should use the Audio Chord Wizard to determine the tempo, key and chord progression. If the song was originally recorded with a metronome or drums, you probably can discard the tempo map and use the known tempo. If not, the tempo map will help the new tracks follow the original mp3 variances. If you cannot obtain a usable tempo map using the ACW in RealBand, try the ACW in Biab. Biab ACW doesn't seem to take as many samples as the RB ACW and thus does not react to minor variances quickly enough to throw the tempo map off too far. In other words you won't get one measure at 85bpm, the next measure at 112bm and the following measure at 87bpm as sometimes happens using RB ACW. Don't be afraid to take several runs through the ACW. You will likely get a better tempo map each time as you become more familiar with both the song structure and how the ACW functions.

Also, don't be afraid to experiment with the chord chart. This will guide your new tracks and minor changes in chords can vary what Biab midi tracks and real tracks produce if they are following the chord chart.

Hope this helps and let us know how things work out for you.

Charlie

Last edited by c_fogle; 10/10/14 07:58 AM.
BIAB Ultra Pak+ 2024:RB 2024, Latest builds: Dell Optiplex 7040 Desktop; Windows-10-64 bit, Intel Core i7-6700 3.4GHz CPU and 16 GB Ram Memory.