A or La is the sixth note and the tenth

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 written ...

equivalents are B (B double flat) which is a diatonic semitone above A and G (G double sharp) which is a diatonic semitone below A. "A" is generally used as a standard for tuning. When the orchestra tunes, the

oboe The oboe ( ) is a type of double reed woodwind instrument. Oboes are usually made of wood, but may also be made of synthetic materials, such as plastic, resin, or hybrid composites. The most common oboe plays in the treble or soprano range. ...

plays an "A" and the rest of the instruments tune to match that pitch. Every string instrument in the orchestra has an A string, from which each player can tune the rest of their instrument. "A" is also used in combination with a number (e.g. A-440) to label the pitch standard. The number designates 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 ...

hertz The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that one her ...

. A lower number equals a lower pitch. The

International Standards Organization The International Organization for Standardization (ISO ) is an international standard development organization composed of representatives from the national standards organizations of member countries. Membership requirements are given in Ar ...

(ISO) has standardized the pitch at A-440. However, tuning has varied over time, geographical region, or instrument maker. In 17th-century

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located enti ...

, tunings ranged from about A-374 to A-403, approximately two to three

s below A-440. Historical examples exist of instruments, tuning forks, or standards ranging from A-309 to A-455.3, a difference of almost six semitones. Although the official standard today is A-440, some orchestral groups and chamber groups prefer to tune a little higher, at A-442 or even A-444. Baroque pitch is usually cited as A-415, which is a semitone lower than modern pitch. A0 is the lowest note on the standard

piano The piano is a stringed keyboard instrument in which the strings are struck by wooden hammers that are coated with a softer material (modern hammers are covered with dense wool felt; some early pianos used leather). It is played using a musica ...

. The octaves follow A1, A2, etc. A7 is a few pitches lower than C8, the highest note on the standard piano. The note "A" is not considered to be a certain milestone or mark to hit with voice as, for example, Tenor C is, but it can be extremely demanding in certain

octave In music, an octave ( la, octavus: eighth) or perfect octave (sometimes called the diapason) is the interval between one musical pitch and another with double its frequency. The octave relationship is a natural phenomenon that has been refer ...

Designation by octave

Scales

Common scales beginning on A

* A major: A B C D E F G A * A natural minor: A B C D E F G A * A harmonic minor: A B C D E F G A * A melodic minor ascending: A B C D E F G A * A melodic minor descending: A G F E D C B A

Diatonic scale 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 st ...
s

* A

Ionian Ionic or Ionian may refer to: Arts and entertainment * Ionic meter, a poetic metre in ancient Greek and Latin poetry * Ionian mode, a musical mode or a diatonic scale Places and peoples * Ionian, of or from Ionia, an ancient region in western ...

: A B C D E F G A * A

Dorian Dorian may refer to: Ancient Greece * Dorians, one of the main ethnic divisions of ancient Greeks * Doric Greek, or Dorian, the dialect spoken by the Dorians Art and entertainment Films * ''Dorian'' (film), the Canadian title of the 2004 film ' ...

: A B C D E F G A * A Phrygian: A B C D E F G A * A Lydian: A B C D E F G A * A Mixolydian: A B C D E F G A * A

Aeolian Aeolian commonly refers to things related to either of two Greek mythological figures: * Aeolus (son of Hippotes), ruler of the winds * Aeolus (son of Hellen), son of Hellen and eponym of the Aeolians * Aeolians, an ancient Greek tribe thought to ...

: A B C D E F G A * A Locrian: A B C D E F G A

Jazz melodic minor

* A Ascending melodic minor: A B C D E F G A * A Dorian ♭2: A B C D E F G A * A Lydian augmented: A B C D E F G A * A Lydian dominant: A B C D E F G A * A Mixolydian ♭6: A B C D E F G A * A Locrian ♮2: A B C D E F G A * A Altered: A B C D E F G A

References

External links

Standard Pitch or Concert Pitch for Pianos
by Barrie Heaton

{{Semitones Musical notes