7afdo: Difference between revisions

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{{Infobox ADO|steps=7}}
{{Infobox AFDO|steps=7}}
'''7ado''' is the [[ADO|arithmetic equal division of the octave]] into seven parts of 1/7 each. As 7 is a small odd number, this ADO does not contain a perfect fifth or any reasonable approximation to it, and it is relatively poor for its size at creating traditional tonal music.
'''7afdo''' ([[AFDO|arithmetic frequency division of the octave]]), or '''7odo''' ([[otonal division]] of the octave), divides the octave into seven parts of 1/7 each. It is a superset of [[6afdo]] and a subset of [[8afdo]]. As a scale it may be known as [[Harmonic mode|mode 7 of the harmonic series]] or the [[Overtone scale#Over-7 scales|Over-7]] scale. As 7 is a small odd number, 7afdo does not contain a perfect fifth or any reasonable approximation to one in its root position. This makes 7afdo relatively poor for its size at creating traditional tonal music unless rotated.


== Intervals ==
== Intervals ==
Line 7: Line 7:
! Cents
! Cents
! Ratio
! Ratio
! Decimal
! Interval name
! Interval name
! Audio
! Audio
Line 13: Line 14:
| 0
| 0
| [[1/1]]
| [[1/1]]
| 1.0000
| perfect unison
| perfect unison
|
|
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| 231.2
| 231.2
| [[8/7]]
| [[8/7]]
| 1.1429
| supermajor second
| supermajor second
| [[File:Jid_8_7_pluck_adu_dr220.mp3]]
| [[File:Jid_8_7_pluck_adu_dr220.mp3]]
Line 25: Line 28:
| 435.1
| 435.1
| [[9/7]]
| [[9/7]]
| 1.2857
| supermajor third
| supermajor third
| [[File:Jid_9_7_pluck_adu_dr220.mp3]]
| [[File:Jid_9_7_pluck_adu_dr220.mp3]]
Line 31: Line 35:
| 617.5
| 617.5
| [[10/7]]
| [[10/7]]
| 1.4286
| high tritone
| high tritone
| [[File:Jid_10_7_pluck_adu_dr220.mp3]]
| [[File:Jid_10_7_pluck_adu_dr220.mp3]]
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| 782.4
| 782.4
| [[11/7]]
| [[11/7]]
| 1.5714
| undecimal minor sixth
| undecimal minor sixth
| [[File:Jid_11_7_pluck_adu_dr220.mp3]]
| [[File:Jid_11_7_pluck_adu_dr220.mp3]]
Line 43: Line 49:
| 933.1
| 933.1
| [[12/7]]
| [[12/7]]
| 1.7143
| supermajor sixth
| supermajor sixth
| [[File:Jid_12_7_pluck_adu_dr220.mp3]]
| [[File:Jid_12_7_pluck_adu_dr220.mp3]]
Line 49: Line 56:
| 1071.7
| 1071.7
| [[13/7]]
| [[13/7]]
| 1.8571
| tridecimal submajor seventh
| tridecimal submajor seventh
| [[File:Jid_13_7_pluck_adu_dr220.mp3]]
| [[File:Jid_13_7_pluck_adu_dr220.mp3]]
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| 1200.0
| 1200.0
| [[2/1]]
| [[2/1]]
| 2.0000
| perfect octave
| perfect octave
| [[File:Jid_2_1_pluck_adu_dr220.mp3]]
| [[File:Jid_2_1_pluck_adu_dr220.mp3]]
|}
|}


[[Category:ADO]]
== Scala files ==
* [[Harmd-mix]]
* [[Oheptad]] – same, but starts with 8/7

Latest revision as of 11:08, 23 February 2025

← 6afdo 7afdo 8afdo →
Prime factorization 7 (prime)
Dual sharp fifth 11/7 (782.492c)
Dual flat fifth 10/7 (617.487c)

7afdo (arithmetic frequency division of the octave), or 7odo (otonal division of the octave), divides the octave into seven parts of 1/7 each. It is a superset of 6afdo and a subset of 8afdo. As a scale it may be known as mode 7 of the harmonic series or the Over-7 scale. As 7 is a small odd number, 7afdo does not contain a perfect fifth or any reasonable approximation to one in its root position. This makes 7afdo relatively poor for its size at creating traditional tonal music unless rotated.

Intervals

# Cents Ratio Decimal Interval name Audio
0 0 1/1 1.0000 perfect unison
1 231.2 8/7 1.1429 supermajor second
2 435.1 9/7 1.2857 supermajor third
3 617.5 10/7 1.4286 high tritone
4 782.4 11/7 1.5714 undecimal minor sixth
5 933.1 12/7 1.7143 supermajor sixth
6 1071.7 13/7 1.8571 tridecimal submajor seventh
7 1200.0 2/1 2.0000 perfect octave

Scala files