Amos, The key of F only has one incidental (black note) Bb. Cb is B. So F-2-G-2-A-1-Bb-2-Cb-2-Db-2-Eb-1-F, also known as "three flats" Should be F-2-G-2-A-1-Bb-2-C-2-D-2-E-1-F, also known as "one flat"