8(Berklee Guide). This book by Berklee bass prof Anthony Vitti will help you make your bass lines more creative, unique and memorable. Tap into the groove and evolve your bass lines by using fills. This book brings you beyond the basics and helps you incorporate figures into your lines that are natural to the groove, and applicable to many styles. The play-along recordings let you hear the fills in context, then practice them with a rhythm section. Audio is accessed online using the unique code inside the 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.