Wow, great job! For me, it's the video that hooked me. I see the OP and comments focusing around the audio mashup, which is really good. But, the video is what gives the mashup viral legs.
Without the high quality and polished video, there is no LMFAO tweet. There's no buzzfeed. There is no radio airplay. Without the video, the song is confined to SoundCloud and small audiences.
The probable virality of Steve's song increased exponentially because of the video. The video is what is being linked to, around the web. From forums, to feeds, to tweets, to DJs.
So to Steve, I say thank you for the video. The effort you made in making a front end to your song made me watch it again and again. The polish of your video gave me the desire and confidence to share it with my friends. The video is the reason I downloaded your MP3 and M4A versions, and will be enjoying this song for a long time. (thanks for that).
In conclusion: because the backend (audio mashup) is well engineered, it has the potential to scale. Without the frontend (video), the backend goes unnoticed by the masses, save for a few backend junkies. The magic happens because the high quality frontend (video) gives the engineered-to-scale backend (audio mashup) a linkable, shareable, visual interface.
Great job! Great lesson! Hope you do more!