The gif and mus files come in .zip format. Most modern OSes will open this without a problem, but you might need an unzipping program of some kind such as WinZip. The pdf files can be viewed using Adobe Acrobat Reader.
To view, transpose and print MUS files (inside the .zip files), download Finale Notepad for free.
Kingdom Hearts III
Dearly Beloved III (Transcribed by max05233157)
for Piano | pdf | mus | midi |
Don't Think Twice (Transcribed by FirahFabe)
for Piano | pdf | midi |
Kingdom Hearts Theme
Piano | pdf |