What if the music is from another source? The Metamath music sampler files are a representation of math formulas in music form. For example, you take the formula below for Axiom of Choice equivalent which is:
|Metamath Axiom of Choice|
and that text formula can be interpreted into a Midi music file which you can hear - if your browser supports the QuickTime plug-in. (Most do so you shouldn't have a problem.)
These tunes are not your everyday bump and grind. Some are random tones. Some have interesting patterns. Most do not have a beat and you can't dance to them.
So What Is the Catch?
None really. These are short music bits so they might work best as transitions or quick entry/exits to a video. The author/authors have placed the tunes in the public domain so no worries about flagging a warning from the RIAA.
You can use the files as you see fit but attribution is a wonderful thing. As a precaution, you should keep a copy of the permission page in case there is a question about usage from some robot. You should do that anyway for any music you obtain and use in a video.
There is a minor technical catch to be aware of, these files are in the .mid format. You will have to convert the the file to an .mp3 or .wav music format unless your video editing program can accept Midi sound files.
Most do not. If you have QuickTime, QuickTime Pro or Audacity you can make the conversion from Midi to .mp3 or .wav