thorough bass

Century Dictionary and Cyclopedia

1. n. In music, a figured bass, or basso continuo—that is, a bass voice-part written out in full throughout an entire piece, and accompanied by numerals which indicate stenographically the successive chords of the harmony.
2. n. A system of stenographic marks, especially numerals, thus used with a bass for the purpose of indicating the harmony.
3. n. The science or art of harmonic composition in general: so called because of the prevalence of such stenographic systems: a loose usage. The ordinary system of thorough-bass, that of numerals, appears first in a publication of Richard Dering in 1597, and its earliest systematic presentation was by Viadana in 1612. In this system numerals are used to indicate the intervals between each tone of the given bass and the constituent tones of the chord to which it belongs so far as is necessary for clearness. If the bass tone is the root of a triad, no numeral is used, unless, perhaps, in an opening chord, to mark the desired position of the soprano, or where a previous chord might occasion ambiguity. The first inversion of a triad is indicated either by or simply by 6; the second inversion by . A seventh-chord is marked by 7; its first inversion by or by ; its second inversion by or by ; and its third inversion by , , or simply 2. A chord of the ninth is marked 9, etc. A suspension is indicated by a numeral corresponding to its interval from the bass, followed usually by a careful noting of the interval of the resolution. In two successive chords having tones in common that are held over from one to the other in the same voices, the numerals required to indicate them in the first chord are given, and are followed in the second by dashes to mark their continuance. Every chromatic deviation from the original tonality is indicated. If the deviation occurs in a tone a third above the bass, a♯, ♭, or ♮ is generally used alone; but if it affects a tone already indicated by a numeral, the accidental required is prefixed to the numeral, except that, in place of a♯ thus prefixed, it is customary to use a dash drawn through the numeral itself (as or ). A passage that is to be performed without chords—that is, in unison or in octaves—is marked tasto solo, or t. s. It is practically possible to indicate in these ways every element in the most complicated harmonic writing, so that an entire accompaniment may be presented on a single staff. The interpretation of such a score requires a thorough knowledge of the principles of part-writing. In consequence of the wide-spread use of this system, the first inversion of a triad is often colloquially called a six-chord, the second inversion a six-four chord, etc.

GNU Webster's 1913

1. n. See Thorough bass.
2. (Mus.) The representation of chords by figures placed under the base; figured bass; basso continuo; -- sometimes used as synonymous with harmony.

WordNet 3.0

1. n. a bass part written out in full and accompanied by numbers to indicate the chords to be played