Volume 10, Number 2, June 2004
Copyright 2004 Society for Music Theory
Bret Aarden and Paul T. von Hippel
Rules for Chord Doubling (and Spacing): Which Ones Do We Need?

4.2.2 Range

[1] It is relatively easy to define part-crossing, but part ranges are more ambiguous. The physical voice or instrument does not necessarily define the range of its part. In quartets, Violin I and II parts are played on the same instrument, but the Violin I parts typically have higher range. In choral writing, each singer may have a large vocal range, but the extremes of that range will rarely be used.

[2] We may begin to clarify the issues by looking at the distribution of notes in each part. In choral music, it is sometimes said that each part has a typical range of about an octave and a half.(78) But the extremes of that range are rarely used. In the soprano parts of the Bach chorales, 95% of all notes are contained within the octave E4-E5. Likewise, 96% of the alto notes are contained in the octave A3-A4, and 96% of the tenor notes are contained in the octave F3-F4.

[3] The bass is rangier, however, with the octave A2-A3 containing only 87% of the bass part's notes. If we want a range that encompasses 95% of the bass part's notes, we need nearly an octave and a fifth. The ranginess of choral bass parts may result from the need for large spaces between bass and tenor (see 2.2), or from the need to skip among triad roots.

[4] The discussion above suggests that the following criterion may produce sensible results: the "characteristic range" for a part is defined as the smallest range containing at least 95% of all notes performed by that part. This definition was applied to both the quartets and chorales, and the resulting characteristic ranges are shown in Table 4.2.2a.

Table 4.2.2a.
The characteristic ranges for each part of the chorales and string quartets, using the minimum-range 95% criterion.

Part Characteristic range (95%)
Soprano E-flat4 - E5
Alto A3 - A4
Tenor F3 - F4
Bass F2 - B-flat3

String quartets
Part Characteristic range (95%)
Violin I D4 - D6
Violin II A3 - F5
Viola E3 - B4
Cello D2 - D4

Back to 4.2 ("Random" Triads)
Back to 4 (Data)

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Prepared by
Brent Yorgason, Managing Editor
Updated 03 June 2004