Interesting discussion. I use Mac Harg Hide bags on all my bellows pipes. Now that I’m playing again without so many sweaters on, I’m re-noticing how I can actually feel the bag vibrating on certain notes when playing the Border pipes. I’ve never played my border pipes with anything but this hide bag, so I can’t testify that there would be a difference with a synthetic. But I would be willing to bet that the vibration within the bag would effect (if only a tiny bit) the overall sound of the pipes. I don’t think I’ve noticed this with my smallpipes though. I’ll have to check. The A chanter is an octave below border pipes, so I suppose that’s not terribly surprising.
The timbral difference between using a goatskin vs. a rubber innertube on my zampogna is astounding, Nate; night vs. day…
but when switching between Naugahyde (when I was into that) and L&M-hide on my Uilleann, the difference was unremarkable.
Maybe it’s me? I dunno. Just callin it like I hear it.
I don’t understand how the bag can have an effect on the sound? I could see if it had somethign to do with moisture and cane reeds, but why would it make a difference with plastic reeds. Do you really think that the resonance of the bag can really alter the sound, or could it be psychological? If there is, what would be the musical explanation for this?
I don’t know because I’ve never used anything other than goat.
You get a chanter of any kind, and play it in the mouth. Puff the cheeks out. then pull the cheeks in. There will be a huge difference in the sound. Put a balloon on between the mouth and the pipe. There will be yet another huge difference. So now, why there wouldn’t be a difference in different bags?
I should be the last person trying to explain this, but I think it may have something to do with this fact: When a chanter is making sound, it’s not doing it in one direction. The vibrating air column is moving down the chanter, releasing some of itself out the finger holes, but also moving back up the chanter and releasing some of itself out the end of the reed. Anyone with a better understanding of physics out there?
sound radiates in a sphere from the source, alternating in wavefronts of higher and lesser compressed air that are analagous to the fundamental frequency and spectrum of the source… I forget what happens after that, (it’s been almost 20 years since “acoustics 101” for me)
but I DO know for certain that it gets increasingly complex.
Acousticians and architects spend lifetimes and bazillions of client dollars pouring over the alleged and proven effects of varoius materials on sound. And even then there’s still a bit of ‘black-magic’ to it.
I feel safe to say, from a purely practical perfromers standpoint, the thinner the bag material, the less it will absorb (block, contain) wavefronts form the source. The interactions of refractions ( how much sound bounces back & forth) happening inside the bag probably have considerable bearing too, but hey, it’s abstruse enough already.
and to echo Yuri (hahahaha I love puns ) bag size is critical too. The higher the cubic volume, the more refractions, the longer the wavelength begin refracted, etc, etc, etc.
perhaps the reason the bag has little tonal effect on an uilleann chanter is because the sound vibrations are a long ways from the bag, the little tube leading from the chanter, where most other types of pipe chanters are inserted directly into the bag.
But, while we have talked about the chanter and the wave lengths moving from the chanter; the drones are also attached to the bag. With the drones, except for SSP, the note sounded is lower than that of the chanter. Thus, longer waves. Any part of an object that is vibrating will transfer that vibrations to something physically attached. There also is an attachment by air and any other medium. I feel the drones from my GHB in my chest many times while playing. Therefore, I have an effect on the instrument as an whole. So Nate, removing a lot of sweaters will cause you to feel and effect the vibrations. The vibrations from the reeds cause sound waves, but also the vibrations from the instrument as a whole, i.e. timbre, tone, and other qualities we look for in a good instrument.
I doubt there is a tonal difference. Sound doesn’t penetrate the surface (which is why David Daye’s brass penny chanters sound as good as excellent Uilleann chanters) and doesn’t care what shape the space it is resonating in is, which is why plywood square box bass recorders sound as good as expensive turned ones. As long as there is an open path between the chanter and drone reed(s) so they can couple, the material of the bag should be irrelevant. If you want the technicalities look up Benade’s work on woodwind acoustics.
As to the feel, a Macedonian piper I know solved that by making a Gortex bag that fit inside his sheep skin bag (actually about 10 % larger so it fills the skin tightly). Now he has a bag that feels like leather but never needs to be replaced and will never dry out and leak or rot from breath humidity. He’s been using it for at least 15 years which equals ~5 sheepskin bags in the Seattle climate.
) bag size is critical too. The higher the cubic volume, the more refractions, the longer the wavelength begin refracted, etc, etc, etc.