Page 3 of 3 FirstFirst 123
Results 21 to 24 of 24

Thread: On the fly perfect chord tuning

  1. #21
    f Forte rjsilva's Avatar
    Join Date
    May 2016
    Location
    PA
    Posts
    836

    1 members found this post helpful.
    Quote Originally Posted by jbird604 View Post
    ...Thus we have settled on the Equal Tempered Scale as championed by Bach (or so I've heard) because it allows one to play any piece of music in any key without being too offensive.
    This is actually a common misconception. Bach referred to a well-temperament. In well temperament you can play in all of the keys but each key has a slight different character. Itís not that our predecessors didnít know about equal temperament, but it was actually rejected quite late in western music by some, believing it to remove the different character between keys.

    It wasnít until the 1800ís that the idea of equal temperament started gaining traction, but even then we have strong reason to believe most tuners were still tuning well temperaments even though they meant to be tuning equalóthere was an analysis of fine tunersí attempts I think at the Broadwood piano factory in the late-1800s which revealed very clearly they were still tuning well temperaments.

    I actually did quite a lot of research about this years ago. In what I found itís reasonable to believe that Ďrealí equal temperament wasnít commonplace until the early 1900ís.

    Itís worth saying that many piano tuners today (I wouldnít know about organ tuners) still donít tune perfect equal temperament. Most tuners would simply see it as the beats not quite being perfect, but thatís effectively a well temperament. In my experience as long itís a decent well temperament no one is going to notice.

    I actually canít remember the last time I played a piano that wasnít tuned to what amounts to a well temperament (granted, not on purpose).

  2. #22
    mp Mezzo-Piano samibe's Avatar
    Join Date
    Oct 2015
    Location
    Kaysville, UT
    Posts
    319

    Well I tune a perfectly equal temperament every time.

    I usually set the stretch with an octave, then set thirds between the octave (and one third below), then fill in the notes in between with fourths and fifths. I do check everything with thirds, fourths, fifths, and sixths but I definitely allow a bit of variability in consecutive beat rates. Occasionally, I have to adjust my temperament when I start working up the treble because some of the deviation becomes too wild for my taste.

    To a certain extent, the piano and organ already clash because an organ's harmonic series lacks the piano's inharmonicity (and resulting stretch). That's assuming they were tuned to each and that the temperature and humidity hasn't changed significantly since tuning.

    This thread has got me wondering if the pitch fixing that a lot of pop artists do in editing a studio album uses Hermode tuning or some other pure chord system (which is why they seem so fake sometimes). I've been noticing (while searching for pure chord tuning information) that there are several audio processing programs that seem to have Hermode pitch adjusting capabilities built in.
    Sam

    Home: Yamaha P22 and a modified Allen ADC-4500 ... for now.
    Church: Allen MDS-5
    Files: Allen Tone Card (TC) Database, TC Converter, Chorus/Mixture TC Generator, ADC TC Soundfont, and MOS TC Soundfont

  3. #23
    f Forte rjsilva's Avatar
    Join Date
    May 2016
    Location
    PA
    Posts
    836

    Quote Originally Posted by samibe View Post
    I usually set the stretch with an octave, then set thirds between the octave (and one third below), then fill in the notes in between with fourths and fifths. I do check everything with thirds, fourths, fifths, and sixths but I definitely allow a bit of variability in consecutive beat rates. Occasionally, I have to adjust my temperament when I start working up the treble because some of the deviation becomes too wild for my taste.
    That sounds a lot like a good well temperament Not at all meaning to criticise, I think thatís fine. To me a mellow well temperament is ideal. I think in the process of setting the temperament the pianoís inharmonicity can affect the decisions of an aural tuner. One could argue that an adaptable well temperament makes more logical sense.

  4. #24
    mp Mezzo-Piano samibe's Avatar
    Join Date
    Oct 2015
    Location
    Kaysville, UT
    Posts
    319

    In researching this a bit more, I found a book and a couple articles by William A. Sethares fascinating. They are a bit mathy (which I appreciate) but they also seem very on the ball (or at least as good as you can get when dealing with human perception).
    Parts of the book can be viewed here.
    He has a website with links to his books and articles (1993 Article, 2002 Article, etc.).

    As for how to implement this, I'm starting to figure out how it could be done on a high level, but where the rubber meets the road is a different animal altogether.
    It looks like most synthesisers have an option to adjust the pitch of a midi channel via midi messages (usually to accommodate a pitch bend wheel).
    The tricky part seems to be with dealing with midi channelization. It is easier to implement on a synthesizer because a synthesizer has one voice and only a couple channels worth of midi information. So, taking the unique notes played, assigning them to separate additional midi channels (in a C chord grouping all notes into C, E, and G note midi channels) with an appropriate pitch adjust midi signal, and running that through a series of synthesizer processors is fairly straightforward.
    It gets much more convoluted with organs because the midi from an organ is already divided into multiple channels to capture all of the divisions, stops, expression information, etc. It's looking like I would have to take all of the note information on all of the separate division channels, run an analysis or pull the adjustment info from a table, then split each division midi channel into several more midi channels for each unique note on that division (up to 6 maybe), and apply an appropriate pitch adjust midi signal to each note/division channel. It's admittedly complicated but still doable, I think. I'm really just not sure how I would tackle it with the programs I have (jOrgan and fluidsynth).
    It might be easier to implement a set of 12 (or so) just (or nearly just) temperaments (one for each key). Then a subroutine could check the played notes and pick the temperament that would fit it best (as well as an overall pitch adjustment so that the change isn't too crazy).
    Last edited by samibe; 07-11-2018 at 06:34 PM.
    Sam

    Home: Yamaha P22 and a modified Allen ADC-4500 ... for now.
    Church: Allen MDS-5
    Files: Allen Tone Card (TC) Database, TC Converter, Chorus/Mixture TC Generator, ADC TC Soundfont, and MOS TC Soundfont

Page 3 of 3 FirstFirst 123

Similar Threads

  1. Hammond Model S Chord Organ tuning issues
    By jimmywilliams in forum Hammond Organs
    Replies: 27
    Last Post: 03-08-2015, 07:28 PM
  2. S-6 Chord Organ no chord sounds
    By Grasshopper in forum Hammond Organs
    Replies: 1
    Last Post: 03-25-2013, 05:38 AM
  3. Chord organ (s6) tuning
    By johnny b3 in forum Hammond Organs
    Replies: 4
    Last Post: 11-10-2010, 08:09 AM
  4. Hommond S-6 Chord Organ Chord Button Problem
    By Wildwood in forum Hammond Organs
    Replies: 1
    Last Post: 03-03-2009, 10:09 PM
  5. Replies: 0
    Last Post: 07-12-2007, 01:08 AM

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •