Minecraft wiki entry for Note_Block, associated text: There are 16 different instruments and 25 different pitches per instrument. Pressing use on the block increases the note pitch up a semitone, with a total of two full octaves and a semitone (25 semitones in total) being available for each instrument. The standard range (for harp and pling instruments) of notes span from F♯3 to F♯5. After reaching the highest note, pressing use again resets the pitch back to F♯3, as does breaking the block and picking it back up.