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forced harmonic tuning

Discussion in 'Miscellaneous [BG]' started by Robbie Butler, Feb 25, 2004.


  1. can any one help me ?
    i've heard of "forced harmonic tuning" can any shed some light on what it is and how do you do it ?

    Cheers , Robbie :x (the tone death bass player :O)
     
  2. JMX

    JMX Vorsprung durch Technik

    Sep 4, 2000
    Cologne, Germany
    I honestly never heard that term.

    I found references on google concerning "forced harmonic motion" though...
     
  3. Coutts_is_god

    Coutts_is_god Guest

    Dec 29, 2003
    Windsor, Ont, Canada
    It's when someone makes you learn how to tune with out an Ele tuner.
     
  4. Matt Till

    Matt Till

    Jun 1, 2002
    Edinboro, PA
    When you tune with harmonics is someone holding a gun to your head?
     

  5. We have a winner!
     
  6. Do you just mean tuning it with a harmonic on the E at the 5th fret corresponding with the harmonic on the 7th on the A, etc.?
     
  7. Thor

    Thor Moderator Staff Member Gold Supporting Member

    That is the method I use to tune as well.

    Note that the sine wave dissonance tells you
    whether you are close or far off. In other words,
    when they are not the same, you can hear a sine
    wave from the production of the 2 simultaneous
    tones. It has a cycle. The period of the cycle is
    how long it takes to repeat.

    The longer the period of the wave is, the closer
    the 2 harmonics are together, until they match,
    and you no longer hear the wave.

    A variation of this is used to 'temper' the tuning of
    the piano, where the 'period' of the interference
    of the same note an octave apart is measured
    with a metronome and set slightly sharp as
    you go up from middle C, and slightly flat heading
    down from middle C.

    Bach wrote a song for piano to demonstrate the
    effect, and called it the 'Well Tempered Clavier' .

    People have used the term 'Forced Harmonics' to
    describe what others call artificial harmonics.

    Open bass strings resonate at a given frequency,
    and at certain areas of the string it is possible
    to produce 'bell tones' that represent the string
    vibrating at a denominator of its length, such
    as 1/2 its length, 1/3 its length, 1/4 its length,
    etc. This is called the harmonic overtone series.

    If one were to stop a note on the string with the
    left hand,it is possible to pluck the string with
    the right hand to produce a harmonic not normally
    available on the open string.

    The famous late jazz bassist Jaco Pastorius is
    famous for using this technique. A classic example
    of this is his original harmonic composition
    called 'Portrait of Tracy' on his self-titled album
    from the mid 70's.

    A good understanding of the structure of harmonics
    will do much to enhance your playing and
    your understanding of music theory.
     
  8. jammadave

    jammadave Rudderless ship Supporting Member

    Oct 15, 2003
    Wash DC metro area
    And it can also be noted that 5th/7th harmonic tuning will not get you completely in tune. Close enough for most ears, but thanks to that whole intonation thing (even-tempered vs. just vs. equal vs. whatever else...) a guitar or bass will only be able to get so far in any direction of the fretboard without being a little off. That is to say, even if the harmonics are dead on, for example a 5th interval from one string to the next higher up the neck will not be a perfect interval.

    blah blah blah, end crap about tuning.

    long as your opens and your 12ths are okay with each other, i say play on!

    :D