Pure Sound Instrument?

Subject: Pure Sound Instrument?
From: Doctor John
Date: 02 Jan 01 - 03:41 PM

What instrument produces the purest sound wave (no overtones etc); I suppose it would sound like a set of tuning forks hit with a hammer. But what is the nearest? Dr John.

Subject: RE: Pure Sound Instrument?
From: Uncle_DaveO
Date: 02 Jan 01 - 05:31 PM

Armonica? Theremin?

Subject: RE: Pure Sound Instrument?
From: Richard Bridge
Date: 02 Jan 01 - 05:53 PM

I believe it to be axiomatic that a recorder produces very nearly a pure sine wave.

Subject: RE: Pure Sound Instrument?
From: Matt_R
Date: 02 Jan 01 - 05:56 PM

Try the Chinese erhu.

Subject: RE: Pure Sound Instrument?
From: kimmers
Date: 02 Jan 01 - 10:40 PM

My cat Lucy, when I step on her tail.

Subject: RE: Pure Sound Instrument?
From: GUEST,Guest: John in Kansas
Date: 03 Jan 01 - 02:21 AM

Pop Science traditionally says that, of common instruments, the flute is most nearly able to produce tones with minimal overtones. As usually played, however, there is a fairly rich set of harmonics.
Of more or less 'true' musical instruments, the water glass monsters that were popular briefly about a century ago can be set up to play nearly 'pure' tones. You made the tone by rubbing a wet finger around the rim, and tuned them by adjusting the amount of water in the glass. You can get a pretty good simulation if you have a good (thin wall) apple shaped wine glass. A glass with 'corners' is more likely to produce harmonics.
A few really cheap 'home & family' keyboards, sold mostly in toy stores, once played nearly pure single notes, but the availability of cheap electronics capable of more musical sounds have pretty much displaced them from the market.
If you can train yourself to blow it properly, a glass gallon (wine?) jug can be blown to get a pretty pure tone. The secret here is that the first harmonic is separated far enough, at that low pitch, so that you can control for the fundamental.
I'm not sure why you would really want a 'pure tone for anything musical, since the sound is not particularly pleasing. The harmonics are what make the note. Pure tones might be useful for background music for a cemetary scene in your latest play though.
Some help: "Fundamentals of Musical Acoustics," by Arthur Benade, and.or "On the Sensations of Tone" by Hermann Helmholtz are pretty much THE definitive books on the subject. Both of these are available from Dover for about 15 bucks each. Benade is readable, but probably not something most people would consider light entertainment. Helmholtz will probably bore you to distraction unless you have a real interest in the physics of the thing. Note that Helmholtz was NOT a musician, and he made a few mistakes in his descriptions of how instruments work in practice, but since he was using ancient technology, he describes a lot of things that a dedicated sound nerd could do for him/herself.

Subject: RE: Pure Sound Instrument?
From: IanS
Date: 03 Jan 01 - 08:41 AM

All waveforms can be synthesised by adding sine waves of different amplitudes and frequencies - this is called a Fourier series. This is the basis of FM synthesis as used in the Yamaha DX7 synthesizers which were very popular in the 1980's (more modern synths tend to rely more on adding and procesing sampled sounds). A single sine wave is the purest sound possible as it contains only the fundemental frequency with no overtones. Most synths (pure samplers aside) are capable of generating a reasonable single sine wave, but as has already been noted it sounds pretty boring.

Ian S

Subject: RE: Pure Sound Instrument?
From: GeorgeH
Date: 03 Jan 01 - 10:33 AM

And any wind instrument (like any string instrument) will produce harmonics of the fundamental . . the nature of them depending on whether the tube is open or closed. To my ears I've never heard a recorder produce anything like a pure tone; certainly John-in-K's suggestion (flute) seems closer.

G.

Subject: RE: Pure Sound Instrument?
From: McGrath of Harlow
Date: 03 Jan 01 - 11:19 AM

John Kirkpatrick said it was the concertina, in a workshop about things like that.

Subject: RE: Pure Sound Instrument?
From: mousethief
Date: 03 Jan 01 - 11:27 AM

An electric guitar, at the top of the neck, and a violin played at the highest end, when you remove the attack, are virtually indistinguishable. Which makes me think that up at that level you're getting near a pure sine wave. I also understand that a piccolo, played near the top, is very close to a pure sine wave. But when you get down into the lower octaves the overtones come back.

Alex