Google Voice Search command "Play Beatles" or "Listen to X" no longer works.

[RazzMaTazz]

I have an Android 2.3 (Gingerbread) based phone. I used to be able to invoke Google Voice Search and say "Play Beatles" or "Listen to Let It Be" and Google Voice Search would launch the music player app and play that group or song. Now it just does a web search for "Play Beatles" or "Listen to Let It Be". (However, Google Voice Search still launches the appropriate app when I give it commands like "Navigate to Radio Shack", "Map of Denver", "Text message to John Doe", "Call John Smith", etc. I just won't launch a music player anymore.)

Anybody know why or how I can fix it?

I have a feeling that it may be because the stock music player is no longer my default music player. (I mostly use MixZing.)