rjd2 is a Hip-Hop artist best known for the Mad Men theme, which you can hear below. He also has several mp3s available for free, legal download at betterPropaganda.
RJD2 – You Never Had It So Good (YouSendIt Download Page)
*Note: The YSI link is from a promotional company representing RJD2. I did not personally upload the file, and I cannot re-upload it once it expires.