In music, a ghost note, dead note, or false note, is a musical note with a rhythmic value, but no discernible pitch when played. On stringed instruments, this is recognised by the sound of a muted string. Muted to the point where it is more percussive sounding than obvious and clear in pitch. There is a pitch, to be sure, but its musical value is more rhythmic than melodic or harmonic… (source = wikipedia)
Until now I haven’t been confronted with severe dead notes problems yet. I have experienced the phenomenon a couple of times, but not at such a degree that my clients have asked me to intervene.
But it happens that one of my wife’s sitars suffers from this, and recently an extra occasion came with this mail by Toss Levy: “… Dead notes on a sitar have always been a problem. Mostly by careful jawari and work on the taraf bridge and strings, I could get a better resonance. I have found dead-notes to be on most instruments and consider the instruments with a responsive resonance over the entire note range rare but of super quality. For me, and maybe in my ignorance, I have accepted the dead-notes as a sign of a lesser quality instruments… How does one go about solving the dead-note problem ??…” :
From my school-time I always remember an important basic physics law about acoustic resonance (source = wikipedia):
k = stiffness
m = mass
ωn = radian frequency (radians per second)
From the radian frequency, the natural frequency, fn, can be found by simply dividing ωn by 2π. Without first finding the radian frequency, the natural frequency can be found directly using:
k = stiffness (Newtons/meter or N/m)
m = mass(kg)
fn = natural frequency in hertz (cycles/second)
This equation tells me that the resonance frequency is proportional to the stiffness and inversely proportional to the mass of an acoustic system. It sounds logical, and gives us a rather simple tool to influence the phenomenon:
Working on the stiffness includes interfering in the instruments basic wooden construction: tabli, tumba, neck, joint etc. … But this is uttermost time consuming and almost impossible to experiment with, and surely not, on an expensive well-built sitar.
But working on the mass can be done very easy: I did some experiments on adding mass to the ghodi (jawari – bridge construction) and the result is very promising. I have prepared and selected a couple of metal parts (lead) ranging from 10g, 20g, 30g,… to 150g and attached these one by one to the ghodi. And as the formula predicts, the resonance frequency is really shifting down. In my case, with 30g added, from komal GA towards main tonic SA where the amplitude of the resonance has been reduced such that it is almost not heard anymore.
Results (sound samples):
1: original jawari (nothing added)
2: jawari + 10 grams added
3: jawari + 20 grams added
4: jawari + 30 grams added
5: jawari + 50 grams added
6: jawari + 100 grams added
7: jawari + 150 grams added
Comments on the results:
1: Dead note is clearly heard on komal GA, also noticeable on GA. (Never mind the missed NI…).
2: Dead note is already reduced in amplitude and slightly shifts towards RE.
3: Dead notes amplitude is even more reduced and shifts over RE.
4: Dead note is now almost disappeared, reaching SA.
5: Dead note is now completely gone, but the overall sound is losing low frequency range because of the damping effect of the weight.
6 & &7: The overall sound loses more and more low frequencies because of an increased damping effect.
Adding a weight to the jawari can be compared to the act of adjusting a kind of acoustic audiofilter. This implicates that when talking about acoustic waves there are always 3 parameters to keep in mind: fo, the frequency itself; A, the amplitude (how strong is the influence) and Q, the quality factor which is related to Δf, the bandwidth. This means that adjacent frequencies are involved in the proces. The lower the quality factor, the bigger influence will be noticeable on adjacent notes or srutis too. This one can be determinative for the result.
Unfortunately it is not a linear but an exponential equation. The result of the operation becomes stronger and stronger OR lesser and lesser at an exponential rate… This means that the practical adjustable range will be limited, and probably difficult to measure. Trouble might be to find a good starting weight. But, patience is a golden virtue…
I have observed sitar makers all over India, especially in Benares where I lived over ten years, but I never heard them talk or demonstrate about dead notes. I think this is a western luthier’s concept.
In the sound samples you have above that show the gradual increase in weight, what was the original weight of the bridge in grams before you started?
Also what is the average weight in grams for most high grade sitar bridges?…..if anybody knows?
Email me email@example.com
The original weight of the bridge is 39g. But this Elforyn™ bridge is slightly smaller than a normal bridge. Normal high grade sitar bridges weigh average 43g (bone), 54g (stagghorn), 41g (ebony)…
Hi Ananda, I have tried this on my sitar and I think it has also slightly increased sustain in the middle of the neck….. I am always looking for that little bit more sustain when playing alap style meend with murkhi….. i am quite sure it has added sustain……. am i deluding myself or could adding weights to the bridge explain this? The weight I used was 46g (i just used a clip on dunlop guitar capo).
Hello Adam, thank you for your report. Your experience is correct. Sustain is inherently directly proportional to the weight (and stiffness of the system). If you add weight to the head of the sitar you will also experience more sustain… but also more weight to carry!! And, unfortunately, sometimes loss in low frequency response.
thanks very much for this article. The result sounds amazing.
I’m playing sitar for many years (Pathak gharana).I own 3 sitars, all with the same resonance problem, so i will try your technique and will tell you about the results
Wolvega – the Netherlands
Great article and congratulations. Due to your work the process is now clear. Of course every sitar will be different and more experiments are necessary but in time I’m sure you will receive more valuable data from colleagues involved with this problem. Then the process can become more refined and accurate.
Thank you Ananda for your great work, you’re a real source of inspiration.
Warm regards, Toss Levy
very interesting matter,like to discuss this once with you personally…
You are welcome…!!