MIDI files are very small and can be played back if your browser has a MIDI plugin.
PDF files can be viewed and printed using the free Adobe Acrobat reader.
Finale files can be viewed and played using the free Finale NotePad program. Note that you may need to right click the link to the Finale files and tell your browser to save or download the file.
And here is the Contra Dance that will be danced at the party.