YES!
That is the short answer to your question. But creating a business plan is one of the most important things that you can ever do. Anyone that is trying to build a business around their music and has not gotten a business plan written, is NOT serious about making a living from this industry and here is why:
1. When you create a business plan you start to outline exactly how it is that you are going to be making money.
2. You start to understand your own value and the value of your work. This is important for setting pricing.
3. Competitor analysis. If you know what others are doing well in their business you can start thinking of ways to improve it.
4. With a business plan in place, you start to understand how to provide a consistent experience for all of your clients.
5. If trying to get investors, yes, they will probably want to see how you have mapped out your business. Especially how you plan on growing.
If you don't know where to get started, look up Freelance Business Plan by Regina. That is where I started before creating an official business plan. I hope this was helpful!
Mark | MhinoProductions.com