Master guitarrist Ralph Towner’s book “Improvisation and Performance Techniques for Classical and Acoustic Guitar” published by Hal Leonard in 1985 has been out of print for at least 20 years. A must read for any classical and jazz guitarrist with an inkling to improvisation, it reveals many of the inner workings of the unique sound developed by Towner over 40 years of guitar playing. Chapters cover several techniques, including damping and chordal plucking, finger combinations, left- and right hand techniques, arpeggio, harmony, scales and voicing. Over 60 exercises and the scores of several of Towner’s most famous compositions, including Distant Hills, Zephyr and Beneeath An Evening Sky, are also included. In the introduction, Towner writes that “the intention of this book is to provide you with musical instruction and material to assist you in learning improvisation, along with fundamental tone production and performance techniques. It is my hope that the content is accessible to a wide range of player skills, including those with minimal experience on the classical or acoustic guitar”. An important element in Towner’s music and playing technique is what he calls polymetrical rhythmic groupings: the implication of two or more time signatures occurring simultaneously. Many of the exercises in the book deal with this concept and its many variations. This is a phenomenal volume, highly recommended to any guitar player and all enthusiasts of Towner’s music.