Not sure what your objective is with the site so I have made some assumptions and here are few simple things I would do:<p>a)Get more info above the fold. There is so much space which can be utilised.
Ex: The left category bar can be pulled up so viewers at first glance can see the entire inventory and choose directly without having to scroll down. Give them the answer before they ask.
b)Since albums/art work are the main part of your site I would suggest getting a slider/carousel style template so you can give more info in less space. Ex: TheFilmReview.com (see how they use the slider to their advantage, not perfectly done but you get the idea).
c) Since this is a music oriented website, give it more life.
Here are a few examples how a music/band websites should look: <a href="http://www.mybandtheme.com/features/17-beautiful-layouts/" rel="nofollow">http://www.mybandtheme.com/features/17-beautiful-layouts/</a>
d)Single page websites, especially ones which do not have enough relevant content/information, and redirect users to other sites forcing them to purchase products are a hard sell. I would suggest once they click on one of the albums take them to a dedicated page where there is some info about the album (history/concept/production) and on that page populate your affiliate links or redirect people from there. Give users info they are seeking and that will lead to purchase.
All a quick redirect with no relevant info leads to is a high bounce rate.<p>Hope this helps.
A few mechanical things: after you click on back to top the left sides highlighted link is wrong, it would be cooler if clicking on the tab on the left caused a scroll to the appropriate section, im not such a fan of the pink, and lastly, i think the content needs some sort of frame; it looks weird alone. i like the navigation style though. It would be annoying to click on each of the albums and then going back to get more IMO. So, I think it would be cool if a left click caused a modal window to appear with a middle click causing it to open in a new tab. I hope this helps!