Definition of "hexachord" []

• A sequence of six tones with a semitone in the middle, the others being whole tones, that was used in medieval music. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• ""hexachord" on which the present scale was perfected."
• "Of a similar nature is Ut queant laxis, for five voices, in which the tenor sings the isolated notes of the hexachord between snatches of four-voice polyphony."
• "Running longitudinally, there are four channels in it if it is a tetrachord; six, if it is a hexachord; eight, if it is an octachord."