A series of four diatonic tones encompassing the interval of a perfect fourth.
[Greek tetrakhordon, from neuter of tetrakhordos, four-stringed : tetra-, tetra- + khordē, string; see gherə- in the Appendix of Indo-European roots.]
tet′ra·chordal (-kôrdl) adj.
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Indo-European & Semitic Roots Appendices
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