A (musical note)

La or A is the sixth note of the solfège. "A" is generally used as a standard for tuning. When the orchestra tunes, the oboe 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.

A0 is the lowest note on the standard piano. 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 octaves.

Designation by octave

Scientific designation	Helmholtz designation	Octave name	Standard frequency (Hz)
A9	a′′′′′′	Six-lined	14080
A8	a′′′′′	Five-lined	7040
A7	a′′′′	Four-lined	3520
A6	a′′′	Three-lined	1760
A5	a′′	Two-lined	880
A4	a′	One-lined	440
A3	a	Small	220
A2	A	Great	110
A1	A͵ or ͵A	Contra	55
A0	A͵͵ or ͵͵A	Subcontra	27.50
A−1	A͵͵͵ or ͵͵͵A	Subsubcontra	13.75