Erich Andreas
No information is provided about the author, Erich Andreas, in the given documents.
The content only mentions his name as the author of "Guitar Mastery Simplified" but does not offer any biographical details, background information, or insights into his expertise or experience in guitar playing or music instruction.
Without additional sources or data, it is not possible to provide a meaningful summary about the author's life, career, or qualifications related to writing this guitar instruction book.
