One thing to bear in mind: Remember not to change the name of the file extension directly because this won't work properly. If you cannot play WMA music files on QuickTime the way you want, just try to get WMA files converted to a format that is identified by QuickTime. In fact, QuickTime player only supports a limited number of audio formats including iTunes Audio files (.m4a.
If you are a Mac user and want to open WMA files on Mac, say, with QuickTime, you may get disappointed because QuickTime doesn't natively open WMA format. WMA is a format that belongs to Windows systems. You can also put WMA audio files to other media players like VLC, ALLPlayer, MPlayer, RealPlayer, Winamp and so many others. Windows Media Player is the first choice to play WMA files. Based on WMA, WMA Pro, WMA Lossless and WMA Voice are created with different codec. WMA ( Windows Media Audio) is Microsoft's format which is supposed to overtake MP3, but it is not as popular as MP3. How to Play WMA Files with QuickTime on Mac