No sarcasm behind my question.
Your understanding of what that means is crucial to whether you will be able to do what you want to do. I get the impression that we all are assuming you know what it means, and that you are actually wanting to do multitrack.
See a "track" is each voice or instrument you want to hear in a recording. The CD's you listen to are 2 tracks, a left and a right.
If you have a CD that you want to add vocals on top of you will need a way to do multitrack recording, unless you just want to sing on top of a CD(yuck) and re-record it right then as you do it.
A better way would be to import the CD "tracks" into an Audio program on your computer, such as Sonar, Cubase & others, then hook up a mic to a preamp to a soundcard, and record your new vocals into the computer where you can then mix them, add effects, mixdown, and burn a CD of your own, all in the computer.
You don't need a MD or other stand-alone unit for what you are trying to do.
Also with the setup I described you can do more than "1 track vocals", you can layer harmonies, add instruments, sampled beats, whatever you want to try.
If I have misread or misunderstood your level of understanding I apologise, I'm trying to read between the lines of your questions!