B, also known as Si, Ti, or, in some European countries, H, is the seventh note and the twelfth

semitone A semitone, also called a half step or a half tone, is the smallest musical interval commonly used in Western tonal music, and it is considered the most dissonant when sounded harmonically. It is defined as the interval between two adjacent no ...

of the fixed-Do solfège. Its

enharmonic In modern musical notation and tuning, an enharmonic equivalent is a note, interval, or key signature that is equivalent to some other note, interval, or key signature but "spelled", or named differently. The enharmonic spelling of a writte ...

equivalents are C (C-flat) and A (A-double sharp). When calculated in

equal temperament An equal temperament is a musical temperament or tuning system, which approximates just intervals by dividing an octave (or other interval) into equal steps. This means the ratio of the frequencies of any adjacent pair of notes is the same, ...

with a reference of A above middle C as 440 Hz, the

frequency Frequency is the number of occurrences of a repeating event per unit of time. It is also occasionally referred to as ''temporal frequency'' for clarity, and is distinct from ''angular frequency''. Frequency is measured in hertz (Hz) which is eq ...

of Middle B (B₄) is approximately 493.883 Hz. See

pitch (music) Pitch is a perceptual property of sounds that allows their ordering on a frequency-related scale, or more commonly, pitch is the quality that makes it possible to judge sounds as "higher" and "lower" in the sense associated with musical melodi ...

for a discussion of historical variations in frequency.

Designation by octave

Scales

Common scales beginning on B

B major B major (or the key of B) is a major scale based on B. The pitches B, C, D, E, F, G, and A are all part of the B major scale. Its key signature has five sharps. Its relative minor is G-sharp minor, its parallel minor is B minor, and ...

: B C D E F G A B * B natural minor: B C D E F G A B * B Harmonic minor: B C D E F G A B * B Melodic minor ascending: B C D E F G A B * B melodic minor descending: B A G F E D C B

Diatonic scales In music theory, a diatonic scale is any heptatonic scale that includes five whole steps (whole tones) and two half steps (semitones) in each octave, in which the two half steps are separated from each other by either two or three whole steps, ...

* B Ionian: B C D E F G A B * B Dorian: B C D E F G A B * B Phrygian: B C D E F G A B * B Lydian: B C D E F G A B * B Mixolydian: B C D E F G A B * B Aeolian: B C D E F G A B * B Locrian: B C D E F G A B

Jazz melodic minor

* B Ascending melodic minor: B C D E F G A B * B Dorian ♭2: B C D E F G A B * B Lydian augmented: B C D E F G A B * B

Lydian dominant In music, the acoustic scale, overtone scale, Lydian dominant scale, Lydian 7 scale, or the Pontikonisian Scale is a seven-note synthetic scale. : This differs from the major scale in having an augmented fourth and a minor seventh scale degre ...

: B C D E F G A B * B Mixolydian ♭6: B C D E F G A B * B Locrian ♮2: B C D E F G A B * B Altered: B C D E F G A B

Variation of meaning by geographical region

The referent of the musical note B varies by location. See for a discussion on other differences in letter naming of the notes. In the United States, Canada, Australia, the United Kingdom, the Republic of Ireland, and the Netherlands, as described above, B usually refers to the note a

below C, while B-flat refers to the note a

whole tone In Western music theory, a major second (sometimes also called whole tone or a whole step) is a second spanning two semitones (). A second is a musical interval encompassing two adjacent staff positions (see Interval number for more det ...

below C. However, in Germany,

Central Central is an adjective usually referring to being in the center of some place or (mathematical) object. Central may also refer to: Directions and generalised locations * Central Africa, a region in the centre of Africa continent, also known a ...

and

Eastern Europe Eastern Europe is a subregion of the European continent. As a largely ambiguous term, it has a wide range of geopolitical, geographical, ethnic, cultural, and socio-economic connotations. The vast majority of the region is covered by Russia, whi ...

, and

Scandinavia Scandinavia; Sámi languages: /. ( ) is a subregion in Northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. In English usage, ''Scandinavia'' most commonly refers to Denmark, Norway, and S ...

, the label B is sometimes used for what, above, is called B-flat, and the note a

below C is called H. This makes possible certain spellings which are otherwise impossible, such as the

BACH motif In music, the BACH motif is the motif, a succession of notes important or characteristic to a piece, ''B flat, A, C, B natural''. In German musical nomenclature, in which the note ''B natural'' is named ''H'' and the ''B flat'' name ...

and the

DSCH motif DSCH is a musical motif used by the composer Dmitri Shostakovich to represent himself. It is a musical cryptogram in the manner of the BACH motif, consisting of the notes ''D, E-flat, C, B natural'', or in German musical notation ''D, Es, C, H'' ...