Intervals
I'm working on a new solo piece for cello that is both beautiful and difficult.
The thing about Philip Glass's Orbit that makes it difficult are the double-stops, tied together, that change intervals during a shift.
That is, the intervals get bigger or smaller while moving between notes, making it not only challenging to read but to play.
During practice and lessons, I have come to understand the language of intervals, which is both descriptive and specific. "Major third to diminished fourth" and so forth.
What ARE intervals anyway?
In music theory, an interval is a difference in pitch between two tones.
An interval may be described as horizontal or melodic if it refers to successively sounding tones, and vertical or harmonic if it pertains to simultaneously sounding tones.
The intervals I'm talking about in Orbit are vertical.
There is a naming convention for intervals comprised of uppercase and lowercase letters including (P) for perfect, (M) for major and (m) for minor, and numbers (1 = unison, 2 = second, 3 = third) indicating distance between tones.
They come together like this:
P1 = perfect unison
m2 = minor second
M2 = major second
In chromatic scales, the pattern is something like this: P1, m2, M2, m3, M3, P4, P5, m6, M6, m7, M7, P8.
The words "augumented" and "diminished" sometimes show up when describing intervals. These indicate whether a sharp or flat increases or decreases a perfect interval by a semitone. For example, C to F is a perfect fourth. And C to F# is an augmented fourth.
The interval pictured above is P8 - aka, an octave.
More about intervals here:
https://en.wikipedia.org/wiki/Interval_(music)
More about Orbit here:
