How Can Rubato Remain Free Without Losing Its Inner Pulse?

Building a Piano Piece · Season Three: From Score to Interpretation: Building a Performance of Your Own · Article Nine

Rubato is often translated as “stolen time” and followed by a rule of apparent fairness: whatever time is taken here must be paid back by moving faster later. Another tradition of advice says to follow feeling, as if sincere emotion automatically preserves metre.

Each account captures only part of the problem. Performed time includes changes of baseline tempo across a section, phrase-related motion and relaxation, agogic emphasis on a particular event, small asynchronies between melody and accompaniment, and different treatment of cadential levels. They need not all obey beat-by-beat conservation, and they should not all be collapsed into one kind of rubato.

An “inner pulse” does not require every note to coincide with a metronome. It is a continuing field of reference. The performer knows where a departure begins, what it serves, and how it continues or returns. A listener can hear temporal change as the shaping of an utterance rather than loss of control.

Establish a version that works without rubato

Select a short passage and use a controllable tempo. Maintain a basic pulse while realising written rhythm, articulation, harmony and voicing. This is not meant to be mechanically inexpressive. It creates a reference. If harmonic direction, phrase hierarchy and character exist only through repeated slowing, the first problem may be tempo, balance or analysis.

Record the baseline. Mark three kinds of event in the score: places that require continued motion, places where dwelling may be possible, and places where a reference must be re-established. Do not write ritardando at every phrase ending. Beside each proposed timing change, state a function: “delay the resolution”, “enlarge the formal boundary”, “make a melodic appoggiatura audible”, or “enter a new tempo”—not simply “more Romantic”.

Distinguish three forms of temporal freedom

Large-scale elasticity is a tempo curve across a section or longer span, with the whole texture moving together. Because it changes structural proportion, check whether it causes the second half to accelerate accidentally or the conclusion to become disproportionately slow.

Local shaping occurs around a phrase, harmonic arrival or individual note. It can be small enough not to change the perceived baseline. Researchers commonly measure phrase-related timing in expressive performance, but statistical regularities do not prescribe the size of every phrase ending. A study of pulse prediction and timing fluctuations in a Chopin performance uses a particular recording and model. It shows that deviations can have analysable organisation; it does not create a universal Chopin rule.

Inter-voice elasticity occurs when melody, accompaniment or chord tones do not align exactly. Research on early piano recordings documents melody–accompaniment displacement and asynchronous chords, but a performer, decade and recording condition are not synonymous with composer intention. The value of CHARM’s work on early recordings and performance style is to make practices comparable as evidence, not to turn them into new imitation dogma.

What should “repaying time” mean?

Requiring every phrase to have an identical total duration mechanically erases differences between cadences and formal levels. Ignoring longer proportions allows the performance to drift. A more useful principle is structural return: after a local departure, the performer can re-establish pulse—or enter a deliberately changed reference—at an explicable point.

Time a four-bar group or complete phrase rather than correcting each event. Compare total duration and internal route across three takes. If local dwelling varies naturally while each version restores a stable relation at the next structural point, the playing may be free without being loose. If every hesitation accumulates into slowing and the ending must rush to compensate, the temporal design is immature.

This is also why the metaphor of borrowing cannot be taken literally. A performer may not return an identical number of milliseconds, yet a listener needs longer-range proportion. “Repayment” is best understood as retaining responsibility to the larger pulse and form.

The rubato-baseline test

Make four versions of one passage:

1. Baseline: stable pulse with only indispensable syntactic boundaries.
2. Melodic: accompaniment retains a reference while melody moves within limits.
3. Global: all voices participate in the tempo curve.
4. Reduced: remove half the conspicuous deviations from the preferred version.

Randomise playback. Score six outcomes: is the pulse still predictable; is harmonic arrival clearer; does the melody remain natural; does accompaniment sound dragged; is the long line intact; and is one device repeated excessively? The reduced version often identifies necessary events. If removal causes no expressive loss, the former delay was probably habitual.

Then conduct a silent-beat test. During playback, without the score, maintain a larger beat unit mentally or physically. The goal is not to align every event. Observe whether the reference and performance can meet again at important points. If there is no sense of when they could rejoin, the performer may lack a stable internal model as well.

Freedom must be reproducible in movement

Rubato is not only an auditory intention; it must be organised physically. Some slowdowns occur because the hand has not prepared its next position. Some accelerations arise from anxiety or from sliding through familiar material. They change time, but they are not therefore interpretive choices.

Test without looking at the keyboard, from a cold start, and at a restrained dynamic. If a supposed expressive dwelling always occurs before a leap and vanishes as the connection becomes secure, it was probably motor waiting. Solve the connection, then decide whether musical reasons still justify time.

Compare three takes. Reasoned rubato can contain natural variation, but its essential direction and structural positions recur. Uncontrolled timing has no such consistency. Research on tempo and piano movement also warns against treating rate as a parameter detached from action: changes in rate alter keystroke and movement organisation.

Do not copy milliseconds from one famous recording

Recordings reveal possibilities. Begin by describing parameters. Does the other performer move the entire texture or only the melody? Does deviation occur before an event, on the arrival, or afterwards? Does the performance resume its former pulse or establish a new one? Then design a version that fits your structural account, hands and instrument.

Copying “wait here” extracts an effect from the proportions that made it meaningful. Research into pianistic timing, articulation, dynamics and pedal finds individual combinations rather than a single signature device. Evidence concerning timbral and expressive individuality therefore supports comparative listening, not instructions to sound like a selected pianist.

Inspect several time scales

One performance can be flexible at note level and stable at phrase level. It can also make every local hesitation plausible while the section drifts continuously. Inspect three scales separately: do neighbouring notes and voices form the intended relation; does a phrase travel from departure to arrival; and do several sections retain formal proportion? Do not condemn rubato merely because a metronome graph shows instantaneous change, or excuse long-term slowing merely because each individual delay can be described.

Listen to accompaniment or bass alone as well. If its reference motion has no direction after melody is removed, melodic freedom may have been achieved by dragging the structure. If it is so rigid that melody sounds pasted on top, their relation needs adjustment. Inner pulse is ultimately coordination across levels, not an invariant click concealed beneath the music.

A final judgement

Mature rubato passes four conditions. A perceptible reference exists before departure. Departure responds to phrase, harmony or form. Long-range proportion survives local effect. The performer can preserve direction from a cold start and on another instrument rather than reproducing fixed seconds.

Freedom is not escape from metre. It is the use of time to carry musical structure while remaining in a responsible relationship to pulse.

Inner pulse is not a fence imprisoning rubato. It is the condition that lets departure be heard as departure and return as return.

Primary sources and further reading

• Pulse prediction and timing fluctuation in piano performance
• CHARM on early piano recording, rubato and asynchrony
• Listening responses to expressive and mechanical performance
• Tempo and expressive movement in Romantic piano excerpts
• Timing, articulation, dynamics, pedal and individuality in piano performance

Continue reading: Building a Piano Piece series page

If you would like to bring these ideas about listening, understanding, and practice to the keyboard, you might try ScoreFlow, an app I developed to make score reading and daily practice flow more naturally together.