Piano, Contrabass The Carl Fischer CD Solo Series is designed to help all levels of string bass soloists improve their performance technique by making practice time more productive with the included live" piano accompaniment. Each CD contains beautifully recorded accompaniment, performed by John Walker, a professional pianist withyears of experience accompanying soloists of all ability. Available in 3 graded levels, beginning (Gr. 2), intermediate (Gr. 3) and advanced (Gr. 4-5), this series is sure to improve musicians’ performance technique and confidence.