In jazz theory, a pitch axis is the center about which a melody is inverted.
The "pitch axis" works in the context of the compound operation transpositional inversion, where transposition is carried out after inversion, however unlike musical set theory the transposition may be chromatic or diatonic transposition. Thus if D-A-G (P5 up, M2 down) is inverted to D-G-A (P5 down, M2 up) the "pitch axis" was or will be D. However, if it is inverted to C-F-G the pitch axis is G while if the pitch axis is A, the melody will invert to E-A-B.
Note that the notation of octave position may determine how many lines and spaces appears to share the axis. The pitch axis of D-A-G and its inversion A-D-E will either appear to be between C/B♮ or the single pitch F.
Read more about this topic: Inversion (music)
Famous quotes containing the words pitch and/or axis:
“People do not know the natural infirmity of their mind: it does nothing but ferret and quest, and keeps incessantly whirling around, building up and becoming entangled in its own work, like our silkworms, and is suffocated in it: a mouse in a pitch barrel.”
—Michel de Montaigne (1533–1592)
“He is the essence that inquires.
He is the axis of the star;
He is the sparkle of the spar;
He is the heart of every creature;
He is the meaning of each feature;
And his mind is the sky,
Than all it holds more deep, more high.”
—Ralph Waldo Emerson (1803–1882)