©1993 Psychomusicology CHORDAL-TONE DOUBLING AND THE ENHANCEMENT OF KEY PERCEPTION

The choice of doubled pitches in the spelling of triads in Western four-part harmony is shown to correlate strongly with Krumhansrs tonal hierarchy. A study of chord spellings in 50 chorale harmonizations by J.S. Bach shows that Bach doubles those pitches that are predicted to most enhance the perception of the prevailing key. Krumhansl's tonal hierarchy accounts for a number of tradi-tional music-pedagogical recommendations, including why composers avoid doubling the leading tone. In Western harmony consisting of four or more parts, composers have some liberty in choosing which tone of a triad may be doubled—that is, which of three pitch-classes may be duplicated. Over the centuries, music theorists have proposed a number of recommendations concerning what tones are best doubled in the spelling of chords. In general, the doubling of the root of the chord is preferred, although theorists have identified many ex-ceptions to this principle. Horwood (1948), for example, recommends dou-bling the root in the /, IV, and V chords, whereas either the root or third ma