Exercise 21 introduces syncopation. The right hand is holding notes across measures. Although lesson isn't particularly challenging; it is extremely fun to play. Left Hand:The is no change in the left hand; it plays the same bassline as in exercise 20. Keep playing! If you need a copy of the book, please use the information below to get yourself a copy.Basic Blues for PianoBy Ron PayneCopyright (c) 1984 by HAL LEONARD CORPORATIONInternational Copyright Secured All Rights ReservedItem# 00240075 - US$24.99 - Available for purchase from local music retailers. Used by Permission of Hal Leonard LLC