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Harmonics

Discussion in 'Technique [BG]' started by iplaybass, Oct 24, 2000.


  1. iplaybass

    iplaybass Guest

    Feb 13, 2000
    Germantown, TN
    ALright, stupid question of the day, what are harmonics?
     
  2. Steve Lawson

    Steve Lawson Solo Bass Exploration! Supporting Member

    Apr 21, 2000
    Birmingham, UK
    Ok pick up your bass - now touch the G string at the 7 fret, right over the top of the fret. Don't push the string down, just touch it.

    Now pick the string quite hard with your left hand, and you 'should' get a high pitched 'chime' like sound from the string, way higher than the D note that is at that fret when you push it down...

    That's a harmonic. It's what happens when you divide the string into fractions, thus causing it to vibrate along a fraction of it's length, rather than the full length, so touch it at the 12th fret and you split it in half, 7th fret into 3, 5th fret into 4, 4th fret into 5 and so on...

    listen to portrait of tracey by Jaco, there's loads of harmonics on that...

    cheers

    Steve
    http://www.steve-lawson.co.uk
     
  3. Bruce Lindfield

    Bruce Lindfield Unprofessional TalkBass Contributor Gold Supporting Member

    Actually, while Steve is right in the context of Bass technique - which this is ! ;) - harmonics are present in all music and the relationship between the fundamental of the note which gives it its pitch and the number and volume of the harmonics, give the sound its character or timbre. For example, a flute note is almost pure and free of harmonics, except at its "attack", whereas richer sounds like a violin section or at the extreme, a church bell, have lots of harmonics present in the sound which determine the character of the sound, which allows us to identify the sound as a bell or a violin.

    This is part of the history of how music synthesisers were developed - you can actually build up sounds from scratch by adding harmonics and the basic building block in this "additive synthesis" is the sine wave, which is generally the purest tone that can be produced and similar in sound to a flute without any attack. Different types of synthesisers use different methods for adding the extra harmonics to the more basic sounds like sine waves, square waves etc.

    This is a simplified explanation, but you should be able to find a lot about this on the net of you are interested - search on "Fourrier Analyis" for example.
     
  4. Steve Lawson

    Steve Lawson Solo Bass Exploration! Supporting Member

    Apr 21, 2000
    Birmingham, UK
    Bruce,

    What a coincidence, I've just started a new thread about this over at http://www.churchbelltalk.com :oops:)

    I'm fascinated by the physics of sound and tone and harmonics - that's perhaps why the E-Bow + holds such a fascination for me - the random harmonic thing, depending on which node point you are closest to...

    cheers

    Steve
    http://www.steve-lawson.co.uk