Where Can I Learn Theory?
Now that you know some of the things theory can help with, you still need to know where to find all this precious information. Will you have to take ten years off and study in a monastery in northern Bavaria or, even worse, take out a student loan and go to school full time? Luckily, you can start learning on a purely part-time basis and there are several affordable options for doing so.Buy a Book
Hundreds of books are available on the subject of music theory. Check your local library first and get an idea what's out there. Make sure you find a book that starts from square one and covers things in an easy-to-read style. A book on advanced modal harmony isn't a good starting point.
Once you know what you need, you can find it online and/or order from your favorite bookstore. Use a highlighter to emphasize key points. Give yourself tests and put what you learn into practice.
Most colleges and universities have classes in music theory. Call the ones in your area and ask about an introductory music theory class. Have them send you a brochure with a course description. Ask if you can talk to the teacher to see if the course covers the material you need at a level you can understand. If you want a private music tutor, most piano teachers and many guitar teachers are well versed in music theory and will teach the basics for the price of instrument lessons. Another option is to take some theory-intensive piano or guitar lessons. This way you learn theory, performance, and how the two work together, at the same time.Software for Standard Notation
Perhaps the easiest way to learn to read and write music is with a computer program. There are a number of interactive programs available with tutorials explaining the basics. Some let you click and drag notes, print sheet music, hear what your creation sounds like, and move things around until they sound right. These programs can be are also great for writing melodies and arranging.
Hundreds of software programs are now available for various musical applications. Because of this, many large music stores now have a software section where you can buy music software, ask questions, and compare programs to see which one best suits your needs.