jonno - Posted - 11/27/2009:  12:19:47

Hi,

I want to share this super slow motion clip that shows the movement of fiddle strings as the rosin on the bow hair grabs, pulls, then releases the string. The pattern of movement between the bow and the string as well as the waves up and down the string are fascinating.

After seeing this, I learned a lot about the "grab and release" action on string. It is interesting to watch how the D and A strings move in relation to one another. For every three "grab and release" cycles of the A string, the D string moves twice - this demonstrates the 3:2 ratio of a perfect fifth.

This clip comes from a Discovery Channel episode of Time Warp that I saw several months. Most of the show featured Metallica, but there was a short segment with an old-timey band. They took a high-speed video of a guitar plucking two strings playing E and octave apart - you could see the higher string vibrating at exactly twice the speed of the lower string (the 2:1 ratio of an octave). Then they recorded the fiddler as she pulled a down bow across the open A and D strings for about 2 seconds. The slow-motion clip stretches that quick stroke into a minute.

Here's the link: dsc.discovery.com/videos/time-...olin.html

Some of the physics are described in this other link, but the video of the bow/string action is smaller. dsc.discovery.com/tv/time-warp...olin.html

John

wormbower - Posted - 11/27/2009:  12:42:35

It's amazing just how far those strings vibrate, and that they don't bump into each other.

Paul

BanjoBrad - Posted - 11/27/2009:  13:14:52

I remember that episode. I like that show most of the time.

AuldNick - Posted - 11/27/2009:  19:28:05

Wow....It's a wonder that these fiddles don't blow up in our faces.
That's 'a whole lot of shakin' goin' on' !

Peghead - Posted - 11/30/2009:  14:04:48

Great video, thanks. Last week I was describing to a member how to pressurize (load) the string and release it to "pop" the beginning of the note. It's interesting to consider that the sound of a bowed instrument is actually made of hundreds of these string pops in very rapid succession. One appreciates the sound of a violin for its smooth and continuous tonal charactoristics but at it's source it's just the opposite. The sound source is in a constant state of activation and interruption. Each "pop" or unit of sound is abruptly halted as the string "reloads" The video shows each pop as it rebounds. A great way to visualize it is like beads on a string. Also interesting and kind of funny is that the pops themselves are awful sounding as individual units but merge into something quite different. Greg

Edited by - Peghead on 12/01/2009 07:51:10

pinch - Posted - 12/01/2009:  06:13:04

I focused in on the plume of rosin dust coming off of the bow at the end of the video. Now I know why my nose itches so much while I play.

Peghead - Posted - 12/01/2009:  07:58:30

It looks from the scale of the video that it takes about 1/16" of an inch for the bow to make a single pop and rebound on the string. I'm away from my fiddle but if someone knows the average length of the hair we can multiply and figure out about how many pops there are in a full bow stroke. It's several hundred for sure.

Edited by - Peghead on 12/01/2009 07:58:45