Courtesy of the Yamaha Corporation
Can electronic tuners be used when adjusting timpani heads? Yes, but with an important caveat: most tuners respond best to signals with a stable periodicity. In practical timpani terms, this usually means a strong, stable principal tone and a coherent pattern of supporting partials. For timpani, the variables that determine this response include the physical integrity of the head, the mechanical integrity of the instrument, and—most of all—the accuracy with which the person tempering the head is able to coax the pitch-bearing partials out of the broader inharmonic spectrum. The paradox is that once a head has been well-tempered or cleared, most electronic tuners can register pitch extremely well. A better question is: how can electronic tuners be used effectively during the head-adjustment process?
There are some schools of thought that believe the majority of timpani sound need only contain the principal tone, the fifth, and perhaps an octave in the spectrum. Historically, that was often the practical standard because that is about all many heads/instruments could reliably produce. A spectrum with just the fifth and octave above the principal tone can yield a short-term sense of pitch, and this can be musically functional. However, in many practical cases the principal tone decays faster than some secondary partials (depending on head type, drum design, mallets, dynamics, and the acoustic environment), and the fifth can begin to dominate, creating the perception of a pitch shift. This can still convey pitch, but it may not register consistently on electronic tuners when the signal is transient, noisy, or dominated by unstable partial relationships.
Modern timpani can produce a sound rich with quasi-harmonic overtones, so settling for only a principal tone and the fifth is not always an option. Tempering the upper partials to some degree is often necessary. Many early practitioners who wrote about timpani pitch (including Kirby, White, Taylor, and Blades*) spoke of hearing intervals such as the octave, tenth, twelfth, and sometimes the fifteenth above the principal tone. They did not have electronic tuners, but they understood what constituted good timpani pitch and were able to achieve it by ear.
When a player is able to temper the head so that the pitch-bearing partials are strong and form a coherent near-harmonic pattern, a phenomenon called virtual pitch (missing fundamental inference) becomes more obvious. Under those conditions, the ear/brain can infer a fundamental frequency even when that frequency is weak or absent in the radiated sound. Many electronic tuners attempt a similar inference internally; as the spectrum becomes more periodic and “template-like,” the device tends to respond faster and more consistently. Bear in mind that the alignment of these partials is also influenced by the volume of air in the bowl relative to head tension, as well as the prevailing air density when the head is being tempered.
The graphics below illustrate this phenomenon. A notated C3 was played on a 72cm Fiedler timpano and measured with the Cleartune – Chromatic Tuner for iPhone & Android. The pitch that registered on the Cleartune app was a C2, one octave below the notated and sounding pitch C3.
A written/notated C3 was registered as a C2, indicating that tempering produced enough near-harmonic coherence for the missing-fundamental (virtual pitch) percept to be detected by the Cleartune app.
Tempering a Head
Using a different electronic tuner app on an iPhone (insTuner), on the same 72cm Fiedler timpano, when the head was tempered at a low C2, the insTuner registered the pitch as being that of C1.
Virtual Pitch – Missing Fundamental Spectrogram
When sounding a C3 @130 Hz on a 72cm Fiedler timpano, the spectrogram below (click to enlarge) shows the relative frequencies for modes (1,1) through (6,1) as well as activity for the missing fundamental, which would be C2 65.41 Hz. This frequency (C2 65.41) is not a physical vibration mode of the head, but it can appear in analysis as a strong inferred periodicity when the near-harmonic partials are aligned. This spectrogram was generated with the SpectrumView Frequency Analysis iOS App on an iPad2.
Many electronic pitch measuring devices can be used to test the accuracy of timpani pitch, provided your goal is a pitch center that is as stable and near-harmonic as the instrument can reasonably achieve.
Tempering Heads with Electronic Pitch Measuring Devices
Under the proper conditions, electronic tuners can prove to be an invaluable tool to assist in the tempering or clearing of timpani heads. Electronic tuners can register very low frequencies that are difficult for the human ear to identify quickly. Tuners work best once heads have been balanced either by hand or with a device such as the TAP™ Head Gauge (see Chapter 5, Step 4) or a head tension device such as a DrumDial™ (see Chapter 5, Step 5). For more information on how an electronic tuner can assist in tempering, read Chapter 5, Step 6.
Benchmarking Timpani Tuning Gauges
For benchmarking timpani tuning gauges or to measure the orchestra’s “A,” the author recommends the app Cleartune for iPhone or Android. It is inexpensive and registers timpani pitch relatively well once heads have been tempered. It has a function called needle damping (set it to II), and in a quiet room and with the proper mallet you can quickly benchmark your gauges and do spot checks at lug positions. This application works best when no other instruments are playing.
Cleartune – Chromatic Tuner for iPhone & Android
Cleartune is a chromatic instrument tuner and pitch pipe that allows you to quickly and accurately tune up using the built-in mic in your iPhone, iPod Touch or Android device.
Other App Tuners
As the app market continues to grow, other iOS and Android device tuners are appearing that are reported to work well with timpani. They include iDrumTune Pro App, Tonal Energy, Tunable, iStroboSoft products from Peterson, insTuner, Pitchlab, Pano Tuner, DaTuner (Android), and Tuner – Pitched! (Android). As mentioned earlier, once the head has been well-tempered or cleared, most electronic tuners can register the pitch extremely well.
Can electronic tuners be used to tune timpani while performing?
Electronic tuners are generally ineffective for measuring timpani pitch in a live or ensemble situation for the following reasons:
- Timpani radiation is not direct; in ensemble conditions a tuner is likely to pick up nearby instruments rather than your own drum.
- Transient or weak timpani spectra (few strong near-harmonic partials) may not register consistently on electronic devices.
- At louder dynamics, the principal tone often decays quickly and secondary partials (commonly the fifth) can dominate the spectrum, confusing tuners.
- Different mallet choices emphasize different partials and change masking, which can also confuse tuners.
Electronic tuners are extremely valuable when isolating the principal tone at lug positions during the initial mounting and tempering process as described in Chapter 5. They help reduce ear fatigue and can help identify very low frequencies more quickly than the human ear.
iDrumTune Pro App
Considering that this app was designed for tuning drums and not designed as a timpani tuner, it works well for measuring timpani lug tension and pitch in a controlled environment. This app is a keeper. Please visit Drum Sound and Drum Tuning for more information on how to use this app for tuning drums.
The DrumTune Pro app was tested on a well-worn head on a 29″ Fiedler Dresden drum at a low F2 (87 Hz). It was first tested using the Pitch Tuning function with the Target filter off. It would only register in 0.5 Hz increments, which can be problematic at very low frequencies, but it was able to register 87 Hz at each lug. The drum was then tuned to a D3. The Spectrum Analyzer (Fig 1) read a very strong principal tone (mode (1,1)), the fifth (mode (2,1)), the octave (mode (3,1)), and the tenth (mode (4,1)). All of the upper partials are very near harmonic.
After playing on the drum for a bit, the Lug Tuning function with the Target filter off (Fig. 2) was used to clear the head on the same low F2 (87 Hz). After a few attempts, the closest “0” reading for each lug still generated +0.5 for one lug. The Spectrum Analyzer (Fig 3) again reads a very strong principal tone (mode (1,1)), and the fifth, octave, and tenth (modes (2,1), (3,1) & (4,1) respectively) are very proportional to the principal tone. Again, all of the upper partials are very near harmonic.
Tune-bot by Overtone Labs
The Tune-bot, although not designed for use with timpani, can produce satisfactory results for isolating and measuring the frequency at each lug point. It has functions such as pitch/note mode (frequency vs note name), filter mode (high pass/low pass), and difference mode (difference between a lug hit and a target value, with an analog-style display).
The Tune-bot is designed to clip on the counterhoop of a smaller drum and remain stationary when tuning. When doing that with timpani, in order to get it to trigger, you may need a high SPL, which produces too many unwanted partials. A workaround is to remove the clip and move the unit to each lug point to measure frequency; it will then trigger at a lower SPL.
The Tune-bot measures what it is designed to measure; however, it was primarily designed to isolate and measure a single frequency at a time, not a complex tone with a quasi-harmonic spectrum. Your heads generally need to be relatively clear (or evenly tensioned with a DrumDial™) in order to get stable readings. You can then use it to get each lug to correspond to a single frequency, which is musically functional, but it does not necessarily guarantee that the upper partials will line up harmonically. Fine tempering may still be needed to coax the upper partials into a stronger semblance of harmonicity.
What about the Protune Tuner? (Currently Out-of-Business)
In theory, the mechanics of how the Protune tuner works makes complete sense since it measures the vibrational modes of the head and then represents that as a pitch. Users report that Protune often picks up the fifth (mode (2,1)) more than the principal tone (mode (1,1)), especially when the principal tone decays quickly and the fifth sustains longer. The manufacturer states that repeated striking of the head is necessary for the tuner to function properly. Repeated striking of a timpano in a professional situation, no matter how soft, is not always practical. The Protune may function best as a supplemental aid in ear-training rather than as a primary tuning device.
When the author lectures on timpani acoustics, he uses a Protune tuner to demonstrate the strength of the second mode (the fifth) because it can be effective for that. If you strike the drum once with a soft mallet, it may briefly register the principal tone, but it often shifts to reading the fifth shortly afterward. The User Tips page on the product website details the shortcomings of the device.
Finding the Missing Fundamental
Electronic tuners that display octave register as well as frequency are most useful if you want to measure timpani pitch for the sake of measurement. This type of tuner is often better able to detect the missing fundamental inference. Since the quasi-harmonic spectrum of a well-adjusted timpano can resemble a harmonic series with a missing fundamental, if you can get the tuner to register the pitch as an octave lower than the audible principal tone, that is a strong indicator that your pitch-bearing partials are well aligned. For example: if you are playing a C3 @130 Hz on your 29” drum but the tuner is registering C2 @65 Hz, this suggests the partials are lined up well. Please see the section on Virtual Pitch and Timpani for more information.