Found a solution that worked for me:
- Start regedit.exe
- Navigate to "Computer\HKEY_CURRENT_USER\Software\Microsoft\MediaPlayer\TunerConfig"
- Look for setting PREFERREDMETADATAPROVIDER -- it should have a value "pmpMusicMatch"
- Edit the setting PREFERREDMETADATAPROVIDER, and clear the value so you have a blank value
- Save / exit regedit.exe
- Restart Windows Media Player, you should be restored back to fai.music.metaservices.microsoft.com
What an unnecessary pain in the proverbial.
Update: this DOES NOT WORK any more.
Microsoft appear to have strangled this option off entirely. We are now stuck with the much lesser offering that is "musicmatch-ssl.xboxlive.com".
Microsoft: thanks for nothing.