I like the idea of taking a real performance, and mixing it into a full song, and I think this piece has an interesting melody.
However, the song itself is kind of shoddy in technical aspects. It doesn't build very well, and many of the chords are off-beat with the main theme. I'm thinking if you try something like this again, you should plan further ahead on how the pieces will fit together.
As you mentioned, it doesn't look like you poured enough time into this piece, and that should be something for you to consider next time. That is really all I have to say.
-Fubaka