Music is jarring along with speaking volume.
Your voices don't show a lot of differences, just you mostly speaking at slightly different speed, or mildly different tone. My best advice is make sure that you're focused on genuine variety from the start. The music is competing with your voice as well, which isn't something you should really want at all. If you're looking for something that shows commercial viability, you need to really give this a bit more polish, so I hope to see something down the road!
You know now that I look back at this I see what you mean. When I made this I wasn't exactly sure what to do for a commercial demo so I just kinda threw together a few sample's of things I heard on the radio. But I do understand where you are coming from, a demo should be showing everything one can do. As for the music I do suppose it could be toned down a bit as well. Thank you very much for your honesty and critique!