OK, lets start again. I think we've gone off at a tangent! "Pitch control" is to do with mixing (e.g. mixing CDs or records) and speeds the music up or slows it down. If you want this, then go with our earlier suggestion. But now I read your OP again, I think perhaps that's a red herring? Do you actually mean you need to be able to turn the volume up and down on the mike? If so, you simply need something with a fader, or volume control for the mike,
"I thought we could just feed the mike through the CD player (like a ghetto blaster type thing)" I won't repeat DP's response work for word (too many swear words 
) but the gist is that this is a bad idea because the sound will be awful, you won't be able to adjust the volume on the mike so the level of music and voice will probably be awful.
What you need is a basic 4 channel mixer. (4 channels gives you more options if you want to plug anything else into it in the future)
Here's a very, very basic one from Maplins for just £25.
Or if you want a more knobs one you could pick up a second hand one for about the same price but a bit fancier.
You also need a CD player which can take a memory stick.
You plug the mike and the CD player into the mixer, and then plug the mixer into the amp.
The mixer will have a volume control if it's basic (like the one above) or if it's a little more fancy, it'll have a fader (I think this is what you were thinking of when you said pitch control?) so you can adjust the volume of the mike and the CD players, to get the right mix of volumes.
Here's an example of a mixer with a fader.
Here's another one
It will also have basic EQs so you can fiddle with bass / mids / highs. This will be useful for your DH if you goes into a room and finds he has terrible feedback - he can the EQs on the mixer to sort out any terrible feedback noises.
HTH 