The Guitarist’s New Best Friend! The Lee Oskar QuickGuide booklet for Guitar and Ukulele contains useful instruction and information to get you started on playing harmonica with other instruments. This helpful 20 page booklet includes common chord charts for the most popular Lee Oskar harmonica keys in all 4 Lee Oskar tunings. Major Diatonic – Key of C, Melody Maker – Key of G, Natural Minor – Key of Gm, Harmonic Minor – Key of Cm. Includes chords for guitar & ukulele players!