Start with figuring out who your customers are, where they hang out and how they would search for your items or are your items unaware to them where you will need to introduce it to them. This information is important because it can help you tailor your ad campaigns.
For example, I would do an autopsy on your adwords campaigns and banner ad. Why did these campaigns fail?
1. Did you get a good CTR? If so, perhaps your landing pages need improvement or need to have more for each ad group? Perhaps you need to add an autoresponder where you get their email and sell to them over the course of several emails to help get a better chance of making a sale.
2. Were Your Ad Groups Narrowly Tailored? Did you start with Exact match? If not, did you have an extensive negative keyword list?
3. Did you test to the keyword level and start cutting out keywords that were not converting? Then, did you adjust the pricing to try to make keywords that were making some conversions possibly profitable even if they weren't initially?
1. Is your product a good fit for the content network? A good simple test is the checkout counter at the grocery store. Products that do good on the content network are those that would sell well at the checkout counter of the grocery store. This includes self help, relationships, etc. Basically, anything that is likely to have someone say, this is interesting enough for me to click on the ad and avoid reading whatever I was reading on that site. Yours is music related so it could be.
2. Did you follow a strategy for putting out your ads. For instance, did you do an ad group for each keyword and then remove the keywords that were not performing well. Did you also try out a few different ads to get the one with the best CTR. Then, did you exclude all the sites that are not performing for you? Basically, you need to make sure you are working the campaign and test everything.
After you get a grasp on PPC, then you can start looking at other options like Facebook, Banner Ads, etc. I would suggest you get Perry Marshall's book on Amazon regarding Google Adwords to start with. Try to implement some of his tips and see how that goes. If that still is not working for you, consider getting a consultation from his group (they have 1 hour consultation for $500) or someone else who you can share your campaigns with to see what can be improved. Another option could be to join a forum like the Warrior Forum and mine it for information on PPC. They also have a number of WSOs which can provide you additional information and tips at a small cost.
Basically, if I were you I would read up on Google Adwords and PPC for a couple of weeks. Get books, read articles, ask specific questions of experts on forums, etc. Absorb everything. See what your competitors are doing in this area. There may be some things you should be incorporating with regard to ad copy, keywords, or landing page. Then, after this decide if you are comfortable enough to try out some more PPC. If not, get a consultation from an expert. Then, at that point, you should be ready to take the plunge and be more confident testing out your campaigns. Once you get a good grasp on PPC, then you can consider looking at the other stuff. It will still be there a few months from now so don't worry about chasing down other advertising rabbit holes right now. The main thing you want to make sure you are doing is that you are moving forward and so a week from now, you can honestly say you know more about PPC and then, again a week later, and so on.
Hope this helps.