From your supplied Real Book photo · B♭ · 4/4 · Medium blues. Photo-approved grips only. Printed B♭ and E♭ remain unchanged; dominant-7 shells are recommended for I and IV in this 12-bar blues. Major-6, maj7 and 6/9 are labeled alternatives. This is a comping interpretation, not melody analysis. No melody reproduced.
Unique Chords in Tune (4)
12-bar chart · click any chord
Printed changes, carried through unmarked bars. In m.4, B♭ continues for beat 1; B♭7 is read as entering on beat 2 from its placement after the triplet. That timing is an interpretation of the handwritten spacing. No extra turnaround added.
1. Neck Position Lock (Minimize Hand Movement)Locked to Frets 1–4
Eight-fret view · shifts only when needed. Position settings constrain grip choices, not the displayed view.