Need Help with Offering MP3 Downloads

Hi,
I would like to be able to allow a user to download an MP3 file by clicking on a button (link). Right now I am using “getURL” but on both PCs and Macs it just opens up a media player.

How do I make it so that when the link is clicked, the MP3 downloads to a specified place so that the user can have the file?

Thanks!