It's obvious and been mentioned...
After someone jumps through the enter site hoop and gets mad that their speakers just blared out music they didn't ask for, they then get what is basically a blank page. Your first page has to grab the visitor's attention. by having a blank page with 2 links for brochure and whatever else, you now have a 3rd place you will lose visitors at.
1. get rid of the click to enter site crap
2. get rid of the music player
3. make the first page GRAB the visitor's ATTENTION!
Do those things and you will see a big change in bounce rate.
The site has some awesome artwork, USE it to make people want to view the rest of the site. By hiding it, you fail to use the selling point you have.