Question reguarding the Voice control app

So I've never owned a 3GS proir to this iPhone 4 I currently have which I had for about 3 months now Bit I did own a 3G for about 2 months before I switched to a blackberry. I was playing with the voice control app and its pretty cool and it's pretty accurate when asking it to do something but what I noticed is that it won't play specific songs in my music library when I request it. So is that supposed to happen or is it just not recognizing what I'm asking it?

I know Siri will play a specific song, not sure about voice control on the older phones.