A heptachord, from Greek heptachordos, from ancient Greek ἑπτάχορδος (heptákhordos, "seven-stringed"), from ἑπτά (heptá, "seven") + χορδή (khordḗ, "chord"), is a seven-stringed lyre of ancient Greece, the interval of a seventh, or a (diatonic) scale of seven notes or tones.
7-stringed lyre Most of the ancient greek lyres had 7 strings. Early lyres originate in ancient Mesopotamia.
Interval of a seventh Two intervals are possible: Minor seventh, 10 semitones
Major seventh, 11 semitones
Scale of seven notes A heptachord is based on two consecutive tetrachords.
Basic tetrachords 1½1, ½11, 11½
and the tritone 111
7 modes The 7 modal patterns for the Babylonian heptachords are:
+ Babylonian tonal system Mode Pattern Center note Semitones Tritones kitmum 1½11½1 D 10 0 pītum ½11½11 E 10 0 qablītum 11½11½ C 10 0 išartum 1½111½ G 10 1 embūbum ½111½1 A 10 1 nīd qablim 111½11 B 11 2 nīš tuḫrim 11½111 F 11 2
2 consecutive heptachords
7 consecutive heptachords
6 cyclic consecutive heptachords
Tuning A tuning procedure ‘loosening’ (TU.LU) in Music of Mesopotamia for a 7-stringed instrument based on a transposition to D/D:
‘tightening’ (GÍD.I)
Basic tetrachord with 4 semitones ½1½
Heptachords with 9 semitones ½1½1½1 and 1½1½1½
References
Further reading
External links