I need to divide existing mp3 files into separate tracks because I have a maximum file size that I can upload and download. How can I separate an mp3 file into multiple tracks? I need to turn a 1 hour download into 3 - 20 minute downloads.
You can do it very simply in Audacity. Open the work in Audacity. Put a Label (Apple-B or Control-B) at the top of the piece, at the beginning of cut 2 and the beginning of cut 3.
File-> Export Multiple > MP3.
Audacity will export the work in whatever MP3 compression you picked in the 1.2 Preferences, or in version 1.3, you can pick the quality at the export step.
Is quality critical? This process will give you two MP3 compressions on top of each other, both damaging the sound. The show might sound seriously gargly or bubbly.
There are software packages that can split up your MP3 work without multiple compressions. Google your brains out.