Audio: SATB (0:09)
SATB sings a repeat melody over four ranges. The SATB figure, the score, shows the vocal range of each of the four groupings of the human voice: Soprano, Alto, Tenor and Bass (SATB). The SATB table lists the vocal range of each of the SATB voices in frequency (Hz) and in scientific pitch notation.
SATB is the modern system for orchestrating voices. There are four ranges: Soprano, Alto, Tenor and Bass, hence the acronym SATB. Soprano and bass are collectively known as the outer voices, alto and tenor are the inner voices.
There is no internationally agreed standard for SATB ranges although the data in the SATB table is as good a guide as any.
SATB spans a range of just under four octaves from the lowest bass note, E2 82Hz, to the highest soprano note, C6 1046Hz.
Each of the four ranges in SATB individually spans about two octaves. The outer voices, bass and soprano, occupy separate and distinct ranges that do not overlap. The inner voices, alto and tenor, overlap with each other and with the two outer voices. There are finer gradations for overlapping ranges:
Overlapping voices lead to the phenomenon of voice crossing. It is seen as a problem in some approaches to harmony (but not in melody) and many a writer fights a losing battle trying to prevent it.