A cappella
Sung without instrumental accompaniment of any kind.
Accompanied recitative
Recitative accompanied by the orchestra, as opposed to by basso continuo alone.
Acoustics
The science of sound: how it is produced, transmitted, and received.
Additive form
A compositional technique in which nothing disappears, but new layers are constantly added.
Aleatory music
Music composed using elements of chance.
Amplitude
The size of a sound wave; determines volume.
Anacrusis
A starting note that falls on a beat before the downbeat. Also called a pickup beat or an upbeat.
Anapestic
A poetic meter of short-short-LONG.
Antecedent phrase
In periodic phrase structure, an opening phrase, which sets up the consequent phrase to follow.
Anthem
An English sacred choral work.
Aria
Italian for �air� or �melody�; any lyrical movement or piece for solo voice, usually with some kind of instrumental accompaniment.
Art song
A song set to serious poetry, usually for solo voice and piano, in the tradition of the German Lied.
Atonal
A style of writing that establishes no harmonic or melodic center of gravity; without a tonic, all notes are of equal weight and significance.
