I have recently re-fallen in love with my Colin Kyo drones made by Murray Huggins. To make a long story less short, I started playing Colin Kyo chanters in September of 2008. Sometime later I advised a student to purchase a set of Murray’s pipes and not knowing anything about them I advised my student to buy plain Jane Ezeedrone reeds. When the pipes arrived and we set them up, I clearly remember standing behind my student tuning the tenor drones and noticed this audible ring coming off the tenors. I thought, “Wow, Murray can make chanters AND drones!” I was in graduate school and my wife was in medical school so I didn’t have the dough to get a set myself. A few years pass and a local piper buys a used set of full moose mounted Colin Kyo bagpipes in 2012. I then bought those pipes from him in 2014 when he bought a new set of Colin Kyo pipes half mounted in engraved silver and moose antler. While his set of magic Canning drone reeds didn’t come with the set, I’ve since found my favorite set of reeds for this pipe so far. Ezeedrone! The same reeds I had my student purchase 4-5 years earlier that had that distinct ring off the tenors.

Now, on to how the title and content of the blog post are related. That ring off the tenors is grand, and gives great harmonic blend with the chanter. It makes every note sparkle and sound different from each other. It can also be tedious to tune such drones to the chanter. Those overtones, like the ring off the tenors, are so audible that not only do you have to get the fundamental of each drone audibly aligned, you also have to get those overtones in tune with each other which requires very accurate fine tuning. For some background on that, read this blog post about drone locking.

My tuning routine is as such: 1) Turn off bass and middle tenor, tune outside tenor to chanter low A, 2) Turn on middle tenor and tune to outside tenor and check against low A, 3) Turn the bass on and turn off middle tenor and tune the bass to the outside tenor and check against low A, 4) Turn on middle tenor and make sure all is well. However, this is only sufficient for tenor dominant/audible overtone producing pipes if you’re lucky. I found myself spending a fair bit of time tuning using the above method and then preparing to record a set of tunes only to find that while the drones sounded good against low A, E and a couple other notes would be out of tune just enough for me to notice and not be able to focus on the tunes. That, and I’d never want to intentionally record something for distribution with drones out of tune when I could fix it. So, I had to devise a new method. The new method is exactly the same as the above, except after verifying each set of drone combinations is in tune with low A, I then fine tune each new drone against E (of course, this requires your chanter to already be in tune relative to itself). The method of also checking against E works pretty well I think. You can hear an example of me tuning this way here (note, I often play either high A or D when physically moving the drone; I like D because it has the least harmonic overlap with the drones allowing me to focus on the tuning between the drones whereas high A could obfuscate the drone tuning since it’s just a couple octaves up from the drone fundamentals; make sure your chanter is sounding when tuning drones!):

Tuning

The clip starts with all drones going and you can notice they’re not quite in tune. I shut off the bass and check the tenor unison against low A. I get them settled against D while moving the drone, then low A, and then check against E and you’ll notice they are out of tune against the E even though they sounded fine against low A. This is where you fine tune the overtones. Now, in the clip, before I finish tuning the tenors together, I turn off the middle tenor because I’m going to check the outside tenor by itself against the E first (there’s no point in proceeding if your reference drone isn’t in tune), which it sounded fine so I don’t move it. I then bring the middle tenor back in and you can hear it’s out against the E (since I didn’t fix it a moment ago) so I move it once and check against E again to hear that it is now in tune. On comes the bass with the middle tenor turned off. Again, it sounds good against low A but it’s out of tune relative to the E. 3rd time is a charm for the bass. I almost found it easier to tune the bass against E because its easier to tune the higher frequency overtones of the bass against the E than it is to tune the fundamental to low A. This is because the overtones make the wawawawa sound faster than the fundamental. The bass fundamental wawawa against low A gets to be so slow sometimes it can be hard to hear if it’s my terrible blowing or it’s actually out of tune! The result of tuning with the additional check against E is then heard for the first bit of I Am Proud To Play A Pipe. The first two variations can be heard here as a continuation of the above clip:

I Am Proud To Play A Pipe (forgive the phrasing, I don’t play piobaireachd)

Now I’m eager to try Ezeedrone reeds in all my pipes! We’ll see if it’s Kyo magic, Ezeedrone magic, or a mix of both. Note that I’ve discovered Ezeedrone reeds can’t be set for strength by mouth blowing them. They shut off very easily when mouth blown, disproportionately easy relative to the pressure required to shut them off in the stock. Just a heads up!

Tenor drones produce a fundamental pitch one octave below low A. Bass drones produce a fundamental pitch two octaves below low A. However, both drones produce higher frequency pitches called overtones. The first overtone of each is the next A up. So a tenor drone’s first overtone is the same pitch as the chanter’s low A. The bass drone’s first overtone is the same pitch as the tenor drone’s fundamental. The second overtone of each is an E. So the second overtone of a tenor drone is an E with the same frequency as the E on the chanter.

These overtones, when present with enough amplitude to be heard, manifest as a pleasant ringing sound that seems to hover over the top of the overall drone sound. Many may often hear this ringing only transiently as their pressure fluctuates enough for the ringing to fluctuate in and out. Overtone tuning is very sensitive and here’s why.

Say your chanter tunes at low A = 480 Hz, a common pitch in modern piping. This means your tenors should tune to half that at 240 Hz and the bass tunes at half that, 120 Hz. Say we are tuning our tenor drones and one is at 240 Hz but the other is at 245 Hz. They are out of tune. What you will hear is a beating frequency of 5 Hz, the difference between the two frequencies: 245 – 250 = 5; this is the wawawawawa sound produced by out of tune drones. The overtones produce their own beating frequency. For example, our 240 Hz tenor drone will have an E overtone frequency of 720 Hz. The tenor drone playing at 245 Hz will have an E overtone frequency of 735 Hz. The beating frequency between the E overtones is 735 – 720 = 15 Hz. Therefore, if you can hear this beating frequency it will sound very out of tune. That’s fifteen wawawawa in one second! If you tune the second drone down from 245 to 241 Hz, the fundamental beating frequency between the two tenor drones is now 241 – 240 = 1 Hz and the E overtone beating frequency is now 723 – 720 = 3 Hz. The beating frequencies are smaller (not quieter) so our drones are getting closer in tune.

What does this have to do with drone locking? Well, if you can’t hear the overtone frequencies all that well then you don’t have to worry about their faster beating frequency. All you have to do is get your drone fundamental beating frequency small enough that it sounds as if the drones are in tune. I believe many pipers have often favored bass dominant pipes because they feel they “lock” in tune better. Locking is piper code for drones staying in tune for a long period of time without the need for retuning. I postulate that the perception that bass dominant pipes lock better is due to the lower amplitude in overtone frequencies that make their overtone beating frequencies harder to hear. Thus, the illusion of drone locking is simply due to not being able to hear one’s drones go out of tune because the fundamental beating frequency is still too small to hear and the overtone beating frequencies are too quiet to hear. Note the difference in the words used. Too small to hear means the wawawawa is so slow it can’t be discerned. Too quiet to hear means regardless of how fast it is, you cannot hear it.

I offer an audio sample to guide your understanding. This is made possible by a bum reed the manufacturer has already replaced. This bum reed needed a replacement because it sounds terrible. It produces this huge, nasty overtone that just hurts to listen to. Which makes it a great reed to prove my point, you can definitely hear the fundamental beating frequency along with an overtone beating frequency. You may need to turn up the volume to a setting that is generally considered too loud to be able to discern both beating frequencies. Notice how much smaller the fundamental beating frequency is relative to the high pitched, grating overtone beating frequency. Even near the end of the audio file when the drones are pretty close to in tune, you hear the overtone beating frequency go in and out as I try to find the perfect tuning spot for the second drone. It’s almost impossible and so I will never use this reed in public or even in private, hence why I asked for a replacement.

Tenor drone tuning

EDIT (28-06-2016):

I have received a copy of Mode Locking and the Highland Bagpipe by John Kidd and Peter J. Lindstrom published in Sonus, Vol. 32 No. 2, 2012. I found a couple of statements from the article interesting, they are as follows:

“Preliminary measurements have shown that the effect is real. The phenomenon has not yet been quantified by detailed measurements of instruments of our design. The instruments to be measured must be of this design because those made in the traditional manner, and not modified, will not mode lock.”

“Pipes with abrupt changes in cross section of the drone interiors and cylindrically bored stocks will not mode lock.”

To paraphrase, “single reed” mode locking is specifically the coherence, if you will, of the fundamental with the overtones and occurs very quickly, within the first second of playing a tone on an instrument. “Multiple reed” mode locking is the coherence between two instruments, e.g. two tenor drones.

Mode lock = Phase lock + Frequency lock

By measuring the frequency of the two tenors of the specially designed pipe they determined it took over 30 seconds for them to frequency lock. They made no determination for phase locking.

“Instruments made in the traditional way do not mode lock; however, there are several examples of modified pipes with tapered, but not flared, stocks that have mode locked.” Examples given in the article include: John MacFadyen’s Hendersons (mode locked in 20 minutes), Colin MacMellan’s (Lellan’s?) MacDougals, and Robertson pipes in generally (mode locked in 20 to 30 minutes) due to tapered stocks.

MacDougal designed the bell of the drones (a low pass filter) to allow only the fundamental and a couple overtones to pass. It is also claimed that MacDougals exhibit papered (tapered?) stocks and internal bore chamfering. Mode locking occurs in about 20 minutes.