Hi Lucy,
I really like the visual style of the site - highly appropriate for your type of audience. There's also a lot of friendly copy - it sounds like you're talking to someone when you read through the information - this makes your site welcoming and gives the impression that a real person lives behind the site. There are a couple of typos which need correcting though - hell I've made three just on the other feedback messages I left!
I wouldn't use frames either because they can make your site inaccessible to certain browsers. There's probably no need to use the frames given the content though. The dots stand out a little too much beneath the text and it can make some of the copy hard to follow - but it's a nice background.
As for getting more sales I'd set up a paypal and nochex account immediately - this will make it instantly better. Then when you're secure page is set up that will also inspire total confidence in your site.
Maybe you should set up an e-mail newsletter for registered subscribers so that you can post them new information about artists and other important/related news. This will help build up your potential client base because you'll be taking your website to them via e-mail.
I hope this helps.
Lee
http://www.carnihan.co.uk