The noun gamut has changed its meaning in several ways over time. Its basic meaning is 'range', 'scale' or 'scope [of a quality]'. Among the variations in the meaning of this, there are several misuses which can offend purists if used. Acceptable meanings include the following, of which some are clearly obsolete except in specialized studies, such as that of the history of early music. Gamut has meant, in roughly chronological order:
- The lowest note in the scale recognized by mediaeval musicians (~ G, on the lowest line of the bass stave);
- Etymological note: this explains the background of the word: early (post-Roman) music in the west first labelled six notes, starting with A, and proceeding by whole tones through B, C, D and E to F. When the early writers wanted to name the note lower than A, they had to have recourse to another alphabet. This was, inevitably one may feel, Greek, and they chose gamma (Γ) to label the first note of the scale, its ut (~ 'doh'). The two words coalesced to form gammut (previously written as gamo(u)th, gammouthe, gammoothe, gam(m)uth and even gamma ut and gammaut. (It is now always gamut.)
- Hence, the Great Scale described by the great early music theorist Guido d'Arezzo, or Aretino, (c.990-1050), an Italian Benedictine monk. His Scale, or gamut, comprised in all twenty notes, from G (on the first line of the bass clef - the gamma ut) to two octaves and six notes above (the E on the fourth space of the treble clef), and was built from seven overlapping hexachords (or sub-scales of seven notes).
- It is to Guido that we owe the system of naming notes by single syllables, as in the 'tonic sol-fa system' (see musical notation). The notes were first thus labelled by Guido in this gamut from the first syllables of the lines of an ancient Latin hymn to St. John: for more detail, see Ut queant laxis.
- By what seems natural extension of meaning, gamut came to be used for
- all the notes recognized by musicians, the tones and semitones of which western music is made; and, separately,
- the major diatonic scale; and
- the range, or 'compass', of a particular voice, or instrument.
- This idea, particularly of the third of these, led to the figurative application of gamut as being the range of any quality, such as colours (it is used in this way in computer graphics and the digital reproduction of photographs), or crime (Dickens says, in a protest against the ubiquitousness of the death penalty, "The sounders of three-fourths of the notes in the whole gamut of Crime, were put to death" (Tale of Two Cities (1859) ii. i. 34) or the emotions. (It is in this sense that Dorothy Parker used it in her damning review of Katharine Hepburn's acting at a Broadway first night: "She ran the whole gamut of the emotions from A to B" - although she may never have said it.)