# forced harmonic tuning

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

1. ### Robbie ButlerGuest

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. ### JMXVorsprung 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_godGuest

Dec 29, 2003
It's when someone makes you learn how to tune with out an Ele tuner.

4. ### Matt Till

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

5. ### Nick Bibeault

Jan 10, 2001
Houston, TX!

We have a winner!

6. ### Not Mark Westlake

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. ### ThorGold Supporting MemberIn Memoriam

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