I really take for granted that the sound sucks. But you gotta understand that the site encodes the songs to Lo-fi versions. even if you download the mp3, it's crap.
I really don't know how to mix. It would be great to find a balance between the keys and the guitar. For me ,the keys are a big part of my sound, and i don't want to take importance off them.
I hope you keep on listening. There are a lot more songs for you to check out!!