Advice on chopping samples...

I was listening to Dr. Dre on my iPod (The Next Episode) and I noticed that he sampled a old school song (no surprise)... But, when I went to listen to he original, it sounded flat; unlike Dr. Dre's version. Did he chop that up and cleaned it up, or did he replay the melody??? And if that's the case, how would you go about adding some spice to the sample???

It's a sample. He probably used some eqing and fx to fatten it up