(Guitar Collection). This book with online audio features 25 classic blues riffs arranged for beginning to intermediate guitarists, complete with a "riff history. " Also includes great audio recommendations to help you further your blues knowledge and chops. The audio includes a demonstration of every example in the book. The audio is accessed online using the unique code inside each book and can be streamed or downloaded. The audio files include PLAYBACK+, a multi-functional audio player that allows you to slow down audio without changing pitch, set loop points, change keys, and pan left or right.