If you’re interested in sound (which should be a prerequisite for all musicians,) Yamaha offers a great resource: The Yamaha Sound Reinforcement Handbook. First published in 1988, it’s still highly relevant and applicable today. In fact, many lecturers refer back to this resource. For example, in this video the lecturer explains that older books are some of the best resources, however if you go back earlier than 1988, the technology is outdated and no longer relevant.
To complement the book, Yamaha also released a VHS (a 90’s term for video.) This appears to be a brief summary of the book.
You can also find some free Yamaha clinics online. Here’s a great lesson, featuring a real live band and the lecturer explains the concepts as he goes along.
