Scientific Pitch Notation (Octave Numbers)
Updated: Oct 5, 2020
When discussing a pitch, it's important to be specific. While many notes on the keyboard have the same letter name, the difference in how high or low they are can be dramatic. We'll use vocalists here as an example. In order to be able to sing a piece well, protect and promote vocal health, and improve range, a singer must know how high and low they can safely sing. While colloquial terms such as "high C" are common, it can be more accurate and useful to define precisely which "C" is to be sung.
The system of naming that consists of a letter name, an accidental if necessary, and a number denoting how high or low the pitch is by octave is often referred to as scientific pitch notation. To use our example above, this system of naming could clarify that the C in question is C6 (after all, C5 may be quite a "high C" for operatic bassi profundi (some of the lowest singers by operatic definition, whose ranges typically span between C2 and F4 or thereabouts). While the gravity of discussing pitch specifically is very clear in our vocal example, most musicians can benefit from a way to define where in the span of pitches audible to the human ear.
Using scientific pitch notation, each octave begins on C. The lowest note on the keyboard is the A below the lowest C, making that note A0. The first C is C1. Each subsequent note is also designated as within the first octave until the next C. Using this notation, the notes from the lowest note of the keyboard to the second C are named as follows:
A0, A#0/Bb0, B0, C1, C#1/Db1, D1, D#1/Eb1, E1, F1, F#1/Gb1, G1, G#1/Ab1, A1, A#1/Bb1, B1, C2
This naming structure continues for every note on the keyboard, making the highest key C8.