Middle C About this sound   .

In terms of musical pitch, C or Do is the first note of the fixed-Do solfège scale. Its enharmonic is B, which is by definition a diatonic semitone below C.

Middle C

With a frequency around 261.6 Hz, Middle C is designated C4 in scientific pitch notation because of the note's position as the fourth C key on a standard 88-key piano keyboard.

Another system known as scientific pitch assigns a frequency of 256 Hz but, while numerically convenient, this is not used by orchestras. Other note-octave systems, including those used by some makers of digital music keyboards, may refer to Middle C differently. In MIDI, Middle C is note number 60.

The C4 designation is the most commonly recognized in auditory science, and in musical studies it is often used in place of the Helmholtz designation c'.

While the expression "Middle C" is generally clear across instruments and clefs, some musicians naturally use the term to refer to the C note in the middle of their specific instrument's range. C4 may be called "Low C" by someone playing a Western concert flute, which has a higher and narrower playing range than the piano, while C5 (523.251 Hz) would be Middle C. This technically inaccurate practice has led some pedagogues to encourage standardizing on C4 as the definitive Middle C in instructional materials across all instruments.[1]

In vocal music, the term Soprano C, sometimes called "High C" or "Top C," is the C two octaves above Middle C. It is so named because it is considered the defining note of the soprano voice type. It is C6 in scientific pitch notation (1046.502 Hz) and c''' in Helmholtz notation. The term Tenor C is sometimes used in vocal music to refer to C5, as it is the highest required note in the standard tenor repertoire. The term Low C is sometimes used in vocal music to refer to C2 because this is considered the divide between true basses and bass-baritones: a basso can sing this note easily while other male voices, including bass-baritones, cannot.

In organ music, the term Tenor C can refer to an rank is not full compass, omitting the bottom octave.[2]

For the frequency of each note on a standard piano, see piano key frequencies.

Designation by octave

Scientific designation Helmholtz designation Bilinear music notation Octave name Frequency (Hz) Other names Audio
C-1 C͵͵͵ or ͵͵͵C or CCCC (-uC) Subsubcontra 8.176 About this sound   
C0 C͵͵ or ͵͵C or CCC (-vC) Subcontra 16.352 About this sound   
C1 C͵ or ͵C or CC (-wC) Contra 32.703 About this sound   
C2 C (-xC) Great 65.406 Low C About this sound   
C3 c (-yC) Small 130.813 Bass C About this sound   
C4 c′ (zC) One-lined 261.626 Middle C About this sound   
C5 c′′ (yC) Two-lined 523.251 Tenor C (vocal), Treble C Play  
C6 c′′′ (xC) Three-lined 1046.502 Soprano C (vocal), High C (vocal), Top C (vocal) Play  
C7 c′′′′ (wC) Four-lined 2093.005 About this sound   
C8 c′′′′′ (vC) Five-lined 4186.009 Eighth octave C About this sound   
C9 c′′′′′′ (uC) Six-lined 8372.018 About this sound   
C10 c′′′′′′′ (tC) Seven-lined 16744.036 About this sound   

Graphic presentation

Middle C in four clefs
Position of Middle C on an 88-key keyboard

Common scales beginning on C

  • C Major: C D E F G A B C
  • C Natural Minor: C D E F G A B C
  • C Harmonic Minor: C D E F G A B C
  • C Melodic Minor Ascending: C D E F G A B C
  • C Melodic Minor Descending: C B A G F E D C
  • C Dorian: C D E F G A B C

B sharp

Comparison of notes derived from, or near, twelve perfect fifths (B).

Twelve just perfect fifths (B) and seven octaves do not align as in equal temperament.

  • Pythagorean: 701.955 × 12 = 8423.46 = 23.46 = B+++
  • ET: 700 × 12 = 8400 = 0 = B = C
  • 1200 × 7 = 8400 = 0 = C

This difference, 23.46 cents (531441/524288), is known as the Pythagorean comma.

See also


  1. ^ Large, John (February 1981). "Theory in Practice: Building a Firm Foundation". Music Educators Journal 32: 30–35. 
  2. ^ Wakin, Daniel J. (2007-09-09). "The Note That Makes Us Weep". New York Times. Retrieved 2007-12-12.