Jeremy writes, "I downloaded a torrent file with a .rar extension. It is supposed to be a concert. How do I play a .rar file that is audio?"
The .rar format is a compressed file format, similar to .zip, designed to make files smaller for sharing over the Internet. You can't actually play a .rar file. The file or files inside the .rar compressed file will be the audio file you are looking for. First you need to uncompress the file with WinRAR before you can play it back.
To open a .rar file, first download and install WinRAR. The application is a $29 shareware program if you register it, but you can un-rar files without ever registering.
After installing WinRAR, you can open the .rar file you downloaded from the torrent. The file inside will be the audio file of the concert you want to listen to.