Why did I end up with three MP3 files?

I just uploaded some files with the tab for the tune Dill Pickles Rag. I uploaded four files,

1. PDF with standard notation
2. PDF with the tab notation
3. MIDI file
4. MP3 file created from the MIDI file.

What got posted was the two PDF files, the MIDI file, and three (3) MP3 files. What went wrong? How to I get rid of the two extra MP3 files? Does it create MP3 files on its own?

Also, I tried to upload the source Lilypond file, but the software would not accept a .ly file. I thought that Lilypond was one of the accepted formats for the tabs.