Music sounding odd after downloading onto computer

I recently transfered my music from one computer to the next. I had two seperate accounts so I unploaded my music from one account to download it onto the other account on my new computer. The Music file sounds great on the old computer and on the new computer (while being played on the score website) but when I download it to work on it in musescore it sounds all kinds of messed up. Things are quite when they are supposed to be loud and notes don't sound correct.