Suggested for beginners or intermediate level students that are teens or adults
 
My other go-to series for beginners or intermediate level students that are teens or adults. This series is comprehensive (the "all-in-one course" means that the book contains lesson, theory, and performance pages all in one book) and gives a complete music education. Like its series for children, the adult version is fast-paced and narrow in scope, but concise and direct. An added bonus is that the book uses a chordal approach to teach songs; this is great for students that want to learn pop, jazz, or any such modern style. If you need a link to a specific book in the series, please contact me!