Carillon be sounded together in varied chords with harmonious and concordant effect." The GCNA defines a "traditional carillon" as one played from a carillon mechanical (not electrified) baton keyboard, and a "non-traditional carillon" as a musical instrument with bells, but played by automated mechanical or electro-mechanical means, or from an electrical or electronic keyboard. Since each note is produced by an individual bell, a carillon's musical range is determined by the number of bells it has. Different names are assigned to instruments based on the number of bells they comprise: The Riverside Carillon in New York City has the largest tuned
A♭ (musical note) A♭ (musical note) A (A-flat; also called la bémol) is the ninth semitone of the solfège. It lies a diatonic semitone above G and a chromatic semitone below A, thus being enharmonic to G, although in some musical tunings, A will have a different sounding pitch than G. When calculated in equal temperament with a reference of A above middle C as 440 Hz, the frequency of the A above middle C (or A) is approximately 415.305 Hz. See pitch (music) for a discussion of historical variations in frequency. A/G is the only note to have only one other enharmonic.