"How can I protect my idea?" This is the most common question I get from new clients. Whether it's a new online software, an interesting baby product, some type of new apparel with unusual patterns, or a new method of business for example, the question is always the same. How do I protect it?
So what is the answer? You can't! Well, maybe you can...It depends...Don't you hate this? The truth is you cannot protect vague, broad, conceptual ideas such as, "I want to protect the concept of having a guitar placed within a piece of furniture." That is an example of a broad concept, not an actual invention.
Patents are for inventions, so if you have a prototype or actually mapped out how your invention works, and you have the ability to explain all the parts of the invention and how the parts interact with each other. And also you can explain why your invention is better or solves problem that the prior inventions or patents failed to solve, then you may have a utility patent.
As for the guy that has a guitar within a piece of furniture, that can be protected too, by "design patent" if he actually developed it or has a picture of the exact look he wants protected.
Each invention is a case by case determination of whether it is patentable. See http://patentlawip.com/patents.html for more information.