Click Tracks

The click-track approach provides an auditory pulse -- similar to the sound of a metronome or drum machine -- which is fed to the performing musicians via headphones or in-ear-monitors (IEM's in road-crew jargon). The click track(s) might include unique features to help identify different parts of the beat and different time signatures. For example, the down beat of a measure might have a different pitch than subsequent beats. If the score is in 4/4, the first and third beats might be a different tone or instrument than the second and forth beats. Subdivisions of the beat may be added at key points in the score. Every DAW software program of which I am aware is capable of generating an auditory click track which can incorporate at least one variable tempo map. Even the Bounce Metronome product can generate an auditory click track. However, at the moment, none of the DAW software programs are specifically designed to accommodate the demands of polytemporal music, although Bounce Metronome comes close. There are workarounds to the "single clock" limitation, which I discuss in a different section of this website.

The use of auditory click tracks to achieve synchronization has been refined by Hollywood movie studios over several decades in the production of film scores, and if ever there were a genre where continuously fluctuating tempi must be precisely performed, it's in the field of film scores. Normally, during the production of film scores, the musicians in the studio are listening to the same click track being fed over wired -- or wireless -- headphones. And in some sessions, only the conductor wears a headset. But in polytemporal music, each musician would need to wear a headset in order to hear the unique click track prepared just for their part. Application of the click track technique is still possible, but the complexity of the equipment just increased significantly. Yes, it would be possible to record different instruments (or parts) during subsequent recording sessions (referred to as "stacking"). In this scenario, one could use different tempo maps during the different recording sessions. But the focus of this website is on the composition and live performance of polytemporal music. Besides, Hollywood has no interest in advancing the art of polytemporal music at their expense.

The problem with using different tempo maps assigned to several isolated monitoring channels, so that only a specific player's headset receives the appropriate channel, is not a big issue for a professional recording studio, where the main console can be easily configured to accommodate such a requirement. But if you're performing with a click track coming from a laptop or tablet -- DAW enabled or not -- and certainly if you're using a playback devices such as CD/DVD player, these systems only provide two, i.e. one stereo pair, of line-level, analog audio outputs. As long as you only have two independent tempo maps in your composition, you might be able to make it work...maybe. You will likely run into crosstalk between the 2 channel outputs -- which is deadly if you can hear the click tracks bleeding into each other's background. It all depends on the quality of the equipment you are using.

A more acceptable modification is to add a USB/Firewire Audio Interface (shown above) which provides 4-8 independent, line-level outputs from your DAW system, to which you can then attach a wired or wireless headphone monitoring system. Using professional, high-grade USB/Firewire products in this role should minimize any increase in latency.

Unless your group of musicians includes a couple of audio technicians, you have likely created the demand for at least one audio engineer/technician to accompany each performance of your polytemporal composition, and you have added at least half a day of set up time to the rehearsals. Even if you consider yourself to be technically qualified to troubleshoot the distribution of a click track system, you can't be present at every concert (hopefully), and you can't expect the performance venue to absorb the additional cost.

If you prefer wireless headphones, you'll need UHF transmitters (shown above) working on different frequencies to distribute those 4-8 channels of audio click tracks to the musicians. (Don't even think of using BlueTooth equipment. The lag and unreliability of transmission/reception will drive you mad.) Each performer will have to have a UHF receiver capable of selecting any one of those UHF channels. For the composer, being able to transmit 4-8 polytemporal tempo maps at one time should provide enough flexibility for some serious exploration of this genre.

If you solve all of the technical problems mentioned above, and depending on the number of independent tempo maps you use and the number of players in your ensemble, you'll still need to satify one more common request that occurs with any group listening to a click track with headphones. Each performer will want to adjust the volume of the click track in their headsets during the course of the event. This volume adjustment can be caused by ear fatigue or simply the collective volume of the group as a whole. In a studio environment, this is accomplished by having a small headphone mixer/amp, such as shown above, placed next to each musician's chair so they can make their own adjustments. That means even more equipment will be on stage, and it subsequently increases the complexity of the performance. That's one reason touring pop concerts have "roadies" on staff that travel with the performers. Their job is to setup/trouble shoot/operate/adjust/tear down all of the specialized equipment. In the pop music field, the cost of "road technicians" is already built into the budgets. I know of no classical/contemporary music group that travels with their own equipment technicians, although we're getting close to mandating such a requirement.

Since we've just broached the topic of pop concerts and their use of click tracks, the application has expanded to include other sounds than just an audible click. The latest variation, called a "backing track," can include everything from metronomic clicks and lyrics (obviously not transmitted to the the audience), to the sounds of instruments and voices not on stage (which are transmitted to the audience).

As if all of these problems associated with using click tracks weren't enough, the possibility of "click track bleed" must be considered, especially when there is a large number of musicians using the over-the-ear variety of headsets. During those passages where the musicians are tacet (silent), or there are long rests in the score, the click track keeps clicking, and the possibility of that clicking sound being heard by the audience or escaping into the stage microphones is always present. In a recording studio environment, there are audio engineers on hand to make adjustments. During a live performance, a bleeding click track can be very distracting. And just imagine if that composition is polytemporal, where the tempi of the click tracks do not match. The result would indeed be confusing for the audience, upsetting for the composer and embarrassing for the performers.

If you're thinking of using in-ear wireless headphones during the live performance of Polytemporal music, that's great. Custom ear plugs that are molded to the shape of your ear eliminate bleeding of the click track and provide an isolated, clear sound. However, the cost of such customization can be a little pricey.

In a recording studio where engineers have experience and the time to make adjustments, click track problems can be minimized. But in the case of a live performance by classical or jazz musicians in a concert venue, the lack of setup time, testing and trouble shooting is a significant problem. The hardware and software that produces click tracks, and the engineers to manage the equipment, are not part of the typical, concert venue. String quartets do not travel with a road crew. They also don't perform with backing or lip synching tracks. Only if you are performing rock, hip-hop, rap, folk, or country and western music will the click track option be available. But then, if you are playing in any of the aforementioned genres, you won't be performing polytemporal music.

A company called Soundbrenner has introduced a variation to the click track scheme which substitutes a vibrating pulse in place of an auditory stimulus. According to Soundbrenner, "Using this device, strong vibrations are easily felt against the skin, as the pulse is much stronger than regular [cell] phone vibrations. You can set the tempo of the vibrations according to your liking by twisting the wheel on the [face of the] metronome." There is some debate about whether or not the vibrations can be "easily felt," especially when the vibrations are competing with auditory and visual stimuli. The Soundbrenner methodology does eliminate the necessity of headphones, which has its own set of problem to conquer. The vibrating device -- which comes in two models called the Pulse and the Core -- looks like a large, wireless wrist watch and can be worn on the arm, across the thigh or calf, or even across the chest. The efficacy of using a vibrating pulse has yet to be included in the academic research projects discussed on a different section of this website. According to the manufacturer's published literature, five Core vibrators can be synchronized together via an iOS or Android device, but only one tempo can be conveyed at any one time, and there is no provision for including multiple, varying tempo maps in the software program. (The software app, called "DAWTools," is free and can be downloaded from the Soundbrenner website.) Preliminary reviews suggest that human sensitivity to a vibrating pulse is not as acute as auditory or visual stimuli. However, in the field of contemporary classical music, especially in smaller ensemble works, there may be a niche for this technology once the software becomes modified to allow multiple, simultaneous yet variable tempo maps and tempo ramps.

Let me add that there is a niche in the contemporary classical repertoire that includes the addition of sound effects during a live performance: everything from the sound of whales to wind to crying babies. One might think that these sound effects have been synchronized to a click track. But they haven't. The sound effects are being triggered by a musician on stage -- usually the composer -- sitting at a keypad sampler, adding the sound effects at the appropriate time and controlling the volume. No headsets or clicking track are required.

It doesn't make any logistical or economic sense to advocate for the performance of Polytemporal compositions using a click track -- unless you severely limit the number of tempo maps in use at any one time, which defeats the whole purpose of polytemporal music -- or become satisfied with composing polytemporal duets for the rest of your life.