Accidental
A sign at the left of a musical note that indicates a change in the note’s pitch
Sharp
Raises the pitch of a note one half step above its natural pitch
Double sharp
Raises the pitch of a note two half steps above its natural pitch
Flat
Lowers the pitch of a note one half step below its natural pitch
Double flat
Lowers the pitch of a note two half steps below its natural pitch
Natural
Cancels out an accidental previously in effect