Members windmill Posted March 10, 2013 Members Share Posted March 10, 2013 Found this on another forum"I was hoping Steve or someone might know about any use of the Mixolydian mode with the harmonic seventh, aka septimal minor seventh, in place of the approximately Pythagorean flat seventh. Maybe someone knows of performances or compositions that utilize this "substitution"?"The guy said he was put up to it by JonR Can anyone here explain to me what he is talking about ? Thanks in advance Link to comment Share on other sites More sharing options...
Members 1001gear Posted March 10, 2013 Members Share Posted March 10, 2013 Sounds like gobbledygook for major seventh instead of minor seventh. Or Mixolydian instead of Aeolian. Link to comment Share on other sites More sharing options...
Members JonR Posted March 10, 2013 Members Share Posted March 10, 2013 The question was nothing to do with modes, but was about the harmonic series.The "septimal 7th" is a pitch with a 7:4 ratio with the root frequency, 2 octaves below the 7th harmonic of the root. It roughly corresponds to a minor 7th interval with the root.Try finding the harmonic on your low E between frets 2 and 3, nearer to fret 3. It will be close to a D (10th fret top E), but significantly flat (32 cents). Check the harmonic with your tuner.The OP's point was that you could - in theory - make a perfectly pure sounding dom7 chord by using a 3rd, 5th and 7th tuned exactly to harmonics. And therefore create a mixolydian mode to fit it (adding 2nd, 4th and 6th also tuned to pure ratios).major 2nd = 9:8 (4 cents sharp of equal temperament (ET) = pythagorean, or "3-limit"major 3rd = 5:4 (14 cents flat of ET) = 5-limitperfect 4th = 4:3 (2 cents flat of ET) = 3-limitperfect 5th = 3:2 (2 cents sharp of ET) = 3-limitmajor 6th = 5:3 (16 cents flat of ET) = 5-limitminor 7th = 7:4 = 7-limit, or septimal"5-limit" tuning (based on ratios of 2, 3 and 5) is considered close enough to our standard western scale system."7-limit" tuning is generally too far out to apply much to our 12-note system (except for a a 7:5 tritone), but there is a theory that blues scale is based on septimal tuning.More on the concept of tuning and scales based on the harmonic series and pure ratios here:http://en.wikipedia.org/wiki/Limit_(music)http://en.wikipedia.org/wiki/Just_intonationhttp://en.wikipedia.org/wiki/Septimal_meantone_temperament What I "put him up to" was to ask the question of steve kimock, who is an expert on all this! Link to comment Share on other sites More sharing options...
Members 1001gear Posted March 10, 2013 Members Share Posted March 10, 2013 ... or an intonation thinglol Link to comment Share on other sites More sharing options...
Members jeremy_green Posted March 11, 2013 Members Share Posted March 11, 2013 JonR wrote: The question was nothing to do with modes, but was about the harmonic series. The "septimal 7th" is a pitch with a 7:4 ratio with the root frequency, 2 octaves below the 7th harmonic of the root. It roughly corresponds to a minor 7th interval with the root. Try finding the harmonic on your low E between frets 2 and 3, nearer to fret 3. It will be close to a D (10th fret top E), but significantly flat (32 cents). Check the harmonic with your tuner. The OP's point was that you could - in theory - make a perfectly pure sounding dom7 chord by using a 3rd, 5th and 7th tuned exactly to harmonics. And therefore create a mixolydian mode to fit it (adding 2nd, 4th and 6th also tuned to pure ratios). major 2nd = 9:8 (4 cents sharp of equal temperament (ET) = pythagorean, or "3-limit" major 3rd = 5:4 (14 cents flat of ET) = 5-limit perfect 4th = 4:3 (2 cents flat of ET) = 3-limit perfect 5th = 3:2 (2 cents sharp of ET) = 3-limit major 6th = 5:3 (16 cents flat of ET) = 5-limit minor 7th = 7:4 = 7-limit, or septimal "5-limit" tuning (based on ratios of 2, 3 and 5) is considered close enough to our standard western scale system. "7-limit" tuning is generally too far out to apply much to our 12-note system (except for a a 7:5 tritone), but there is a theory that blues scale is based on septimal tuning. More on the concept of tuning and scales based on the harmonic series and pure ratios here:http://en.wikipedia.org/wiki/Limit_(music)http://en.wikipedia.org/wiki/Just_intonationhttp://en.wikipedia.org/wiki/Septimal_meantone_temperament What I "put him up to" was to ask the question of steve kimock, who is an expert on all this! Posts like this make me truly feel like an absolute moron. I have been playing most of my life yet this barely reads as English. I guess I've been too busy practicing to look this kind of thing up! ... I guess that is good... Link to comment Share on other sites More sharing options...
Members TrickyBoy Posted March 14, 2013 Members Share Posted March 14, 2013 I always though the only purpose of harmonics was to utilize them in conjunction with a whammy bar to produce horse like noises. Link to comment Share on other sites More sharing options...
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