Q: I have a great idea for a music product and need to make a prototype but I'm not very technical. Can you give me any advice on how to make a prototype or any companies that I could pay to make a prototype for me? Or how can I present my idea to a music products company so they can pay me a royalty and design/manufacture it for me? How do I patent my idea?
A: Of all the ways to lose huge amounts of money, making a prototype of your idea is one of the most effective. First, there's a very good chance that others (and possibly many others) have thought of your product idea before, and the reason it isn't already on the market is either 1) others don't find it as valuable as you do, or 2) the necessary engineering or material costs would make it sufficiently expensive that few would buy it.
The first thing to do is to learn the true value of your product idea in the marketplace. One of the biggest mistakes people make is to think that everyone will value their idea as much as they do. First document your product idea, including a clear text description, drawings (or 3D renderings using the free Google Sketchup software) and a realistic customer price. To arrive at the realistic customer price, don't use a price you'd like it to sell for, but rather what it must sell for considering the total parts cost, development cost, manufacturer profit and distributor/retailer profit. Then take an objective survey of people you know and don't know, asking them not if they like it but rather would they definitely buy it at the realistic price you've given. To insure they aren't just telling you what you want to hear, tell them it's someone else's idea, not yours, and don't appear to like or dislike it.
If you still want to make a prototype, try to find a way to make it for no more than $1000 and ideally for free. If you're not technical and you have some friends who are, get them excited about it and ask for free help in exchange for future payment if you make any money later. Important: do everything you can to avoid designing new circuit boards, embedded software (software that runs on the small computers inside self-contained products) and metal/plastic mechanical housings. Very commonly, people start doing this thinking they'll spend only a few thousand dollars then later find they've drained their relatives' savings only to teach themselves how difficult it is.
For many music product ideas, it's possible to--by yourself--create a functional prototype by connecting and reconfiguring a variety of existing low-cost hardware and software music/audio products. It won't be pretty but will be functional and therefore allow you to prove your concept at low cost and therefore give a better demonstration of its usefulness. For hardware and human interface (buttons, knobs, sliders, drum pads, etc.), use existing Midi controllers such as Korg's inexpensive Nano line. Or design your desired control panel on an iPad using cheap iPad apps like MIDIPad or TouchOSC. For foot control, use a cheap midi foot pedal board like a Behringer FCB1010. For the software, it's often possible to prototype your product idea by configuring Ableton Live or other music software. If you like Live and want to dig deeper into functionality, use Ableton's Max For Live add-on. To dig even deeper, learn one of the simple graphical audio/music programming environments like Max/MSP, PD or Reaktor, or learn to program an iPad app.
Regarding presenting your idea to a music products company so they will pay you a royalty and design/manufacturer it for you, this is a highly unlikely scenario. While companies are always interested in their customers' free suggestions, it's very unlikely that they will pay anybody for anything unless they absolutely have no choice. Often they will politely decline to hear your idea because 1) customers' products ideas are rarely unique, and 2) if they were already planning the same idea, they don't want you to later accuse them of stealing your idea. However, if they truly feel it's worth spending their money to make your idea into a product and they feel you have the necessary skills to help them, probably the best scenario is that they may offer you a job.
Regarding how to patent your idea, you can't patent an idea but rather only the implementation of an idea. Getting a patent is another great way to lose lots of money. Plus, having a patent doesn't prevent anyone from stealing your idea but rather simply gives you a better case for infringement if and when you must hire an expensive lawyer to sue them. Again, don't spend any money until you've objectively proven that lots of people would buy your product at its realistic customer price.
Having written the above, it is also true that there are few things more personally gratifying than the exhilaration of creating and using a product that came from your own idea. The good news is that, armed with a willingness to learn some of the inexpensive tools I've described above as well as a little self-honesty, you stand a better chance than ever before of turning your idea into a functioning prototype. If people like it, maybe make a few more, place an ad and sell them yourself while you figure out how to make it cheaper and prettier. Regardless of whether it makes you money or not, you will have taken a fascinating journey, learned valuable new skills, influenced the art of music-making and made a personal contribution to the world of ideas.