Comment by scottious

A better way to think about it is that all letters in the musical alphabet are represented in a musical scale. Some are sharp or flat

D major: D E F♯ G A B C♯

D minor: D E F G A B♭ C

Db major: D♭ E♭ F G♭ A♭ B♭ C

Db minor: D♭ E♭ F♭ G♭ A♭ B♭♭ C♭