Is clock time oppressive or liberating? Yes.

We take clocks so much for granted that it’s easy to forget how radical and recent a development they are. It wasn’t so long ago that clocks had to be painstakingly assembled by hand one at a time. Accurate timekeeping on the order of fractions of a second is a heroic engineering undertaking if you’re trying to do it by mechanical means. Our great-grandparents would have been astounded at how cheap and ubiquitous timekeeping devices have become. In my apartment alone, I can get accurate time measurements from two computers, the cable box, two cell phones, a drum machine, a metronome, an ipod, a thermometer with a built in clock, and a digital camera. Probably the least reliable timekeeping device in here is our analog clock.

Before the explosion of cheap electronics, most people had no external way to keep time so accurately. Before the industrial revolution, there wasn’t much need to. The only reason you would have needed precise timekeeping was for music and dancing.

One school of thought in evolutionary science says that music is a byproduct of other social and cognitive abilities. Another school, the one I find more persuasive, says it’s the other way around, that music and dance are the core capacities that gave rise to language and other complex human social skills. The thinking goes that the precise and nuanced sense of time we developed for our music-making enabled us to coordinate and synchronize our other cooperative group behaviors. Steven Mithen thinks that our rhythmic sense was the precursor to our being able to walk on two feet instead of four.

Whatever the evolutionary back story is, our rhythmic capacity is species-wide and intrinsic. It requires deep focus to keep accurate time in your head, but like walking or eating with a spoon, just about any neurologically intact person can learn how to do it with practice. I know a lot of people who claim to be fundamentally unrhythmic, but that seems to me to be more about anxiety and lack of childhood encouragement than fundamental anatomy. As with language, it’s harder to learn rhythm as an adult, but not impossible.

So we have this ability to track the passage of time with varying degrees of accuracy. We’ve figured out how to assist our counting with cheap, ubiquitous electronics. What does that mean for music? There are two basic approaches to rhythm. There’s clock time and free time, or tempo rubato as the classical music people say, an Italian term that translates literally as “stolen time.”

You might naively expect that the rigid constraint of clock time would be an oppressive limitation on musical expressiveness. Beginning songwriters and arrangers love to throw a lot of tempo and rhythm changes around as a way to create “variety.” In practice, this results in irritating music that’s difficult to play. There are plenty of musical styles that use tempo shifts, from recent European classical to Balinese gamelan, but that stuff needs to be rigorously planned ahead of time and precisely conducted.

People have a finite information processing capacity. Holding the rhythm constant frees up attentional bandwidth for wilder asymmetries of pitch and timbre. All the intricate melodic and harmonic flights in Mozart and Bach go down so smoothly because their rhythms are static and predictable. By the same token, the dazzling rhythmic shifts in Ravi Shankar are manageable because there’s a droning D flat the entire time tying the pitches together.

If you want to improvise, the counterintuitive requirement is that the basic rhythmic framework be predictable. The bigger the ensemble, the more predictable the beat needs to be. The musicians can stretch or embellish the rhythm as much as they want, but without an underlying pulse you get disorganized and patternless noise, which can be exciting in short bursts but gets boring fast.

Some improvising musicians have attempted to dispense with clock time. John Coltrane did some fearless adventuring outside the rhythmic grid in his last few years. Was he successful? Compare two of his free-jazz epics. Interstellar Space is an album of duets between Coltrane and drummer Rashied Ali. The drums form a kind of ambient carpet behind long saxophone solos. While the time and key center are always shifting, Coltrane’s lines have a strong structural logic that makes them relatively easy to follow. It’s intense, but manageable. (If you’re a real Coltrane nerd, check out Lewis Porter’s book John Coltrane: His Life And Music, which includes a complete transcription of “Venus”, the most accessible of these duets.) Ascension, on the other hand, is free jazz played by a group of ten, alternating between horn solos and full-band improvising. Nobody loves Coltrane more than I do, and this album can be cathartic, but mostly all that churning chaos is an ordeal. I respect it, but I can’t say I listen to it too often. Like most people, I find a warmer connection and more of an invitation to imaginatively participate when Coltrane uses a beat.

The paradoxical freedom of clock time extends to recording media. Pro Tools has two different editing settings related to time, grid mode and slip mode. In grid mode, your edits automatically snap to the closest clock time interval, which you can measure in minutes and seconds or bars and beats, whichever is convenient. In slip mode, your edits can fall on whatever time interval you want. As with live performance, Pro Tools’ grid mode is counterintuitively liberating. It encourages experimentation, since dragging, dropping, copying and pasting almost always yield results that make some kind of musical sense. The grid helps you try out new patterns and symmetries easily, and you can keep banging out new combinations until you discover the ones you like. Lining up events in slip mode is possible, but it’s labor-intensive, and it discourages the playful state of trial and error where all the really cool ideas come from. Clock time is such a powerful method of organizing information that you can get pretty good results by banging on a MIDI keyboard more or less at random and then having the computer snap the notes to the closest beat.

I’m not trying to make a value judgment here. Tempo rubato can be beautifully intimate and personal. It’s good for solo or small group performances where the audience listens attentively. But in situations where you want group involvement, dialog and mass participation, the individuals need to deprecate their egos in favor of a shared consensus. Clock time isn’t the only way to get a consensus, but its predictability is a good starting point.