Audacity, an open source multitrack audio editor, has versions for Linux/Unix, MacOS and Windows. If all you do with audio files is play them, then Audacity could be much more than you need. This is not an application for organizing your music collection. It has no fancy search and play functions. Sure, you can use it to listen to your music collection. But Audacity’s main focus is on importing and exporting audio files. Its toolset delves into the realm of editing sound tracks in much the same way graphic editors let you manipulate images.