Wednesday, May 4, 2011

Playing Harmonics

One of the most overlooked aspects of playing harmonics on bowed string instruments is the bowing point. A common cause of harmonics not sounding is that the bowing point is too far away from the bridge.

When playing higher notes, the bowing point usually has to move closer to the bridge, since the vibrating string length is shorter. (The same proportional bowing point to the bridge is closer to the bridge in absolute distance for a shorter vibrating string length.) We usually make this bowing adjustment automatically as our left hand moves up the fingerboard when playing really high notes.

When bowing harmonics, one must remember the bowing point needs to be based on the effective vibrating length of the harmonic and the actual sounded pitch, and not where the left hand actually stops the note. For example, the typical artificial harmonic is played in the low positions, but actually sounds two octaves higher, so it must be bowed as if you were playing the normally stopped note two octaves higher. (In this particular case, the string is actually vibrating in four short segments, like four links in a sausage.) This means the bowing point must be closer to the bridge.

Addendum: I should add that the bowing speed and force (pressure) should also be based on the effective vibrating length of the harmonic and the actual sounded pitch, and not where the left hand actually stops the note.

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