Key signature A minor as each accidental may be notated explicitly as required, or the piece may be modal or atonal. An example is Bartók's Piano Sonata, which has no fixed key and is highly chromatic. If not bound by common practice conventions, microtones can also be notated in a key signature; which microtonal symbols are used depends on the system. The common practice period conventions are so firmly established that some musical notation programs have been unable to show nonstandard key signatures until recently. The use of a one-flat signature developed in the Medieval period, but signatures with more than one
A (musical note) 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 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. A (musical note) La or A is the sixth note of the fixed-do solfège. Its enharmonic equivalents are B ("Heses") which