Ukulele for Everyone! The Comprehensive Ukulele Method Book Four is the fourth in a developmental, comprehensive music program that teaches music theory, songwriting skills, finger picking style as well as strumming and jamming skills. Book four continues teaching students through world music, games and original songs the skills they need to really tap into the joy of the Ukulele. Book four expands our knowledge of key signatures, understanding melody and harmonic melodies and the relationships between our string intervals. We also work on reading and playing double-stops.