Rubato is not something you eat for pudding, it’s an important musical concept that makes a big difference to how music is performed and, consequently, how we respond to that performance. According to Brittanica, “rubato is ‘subtle rhythmic manipulation and nuance in performance. For greater musical expression, the performer may stretch certain beats, measures, or phrases and compact others.”
Or, as Music Theory Academy puts it: “Basically, rubato is when a performer doesn’t stick to the strict rhythms written by the composer, but alters them to give more expression to the performance.”
Until the 1970s and the arrival of drum machines, rubato would be taken for granted in all forms of music from classical to jazz, to folk to pop and rock. A soloist, in particular, would interpret the music in their own unique way by speeding up and slowing down to add character to their performance.
In some cases, a whole ensemble might adapt their pace to suit their preferred interpretation of the piece but, as you can imagine, this is likely to lead to problems in timing. An orchestra or a choir overcomes this by using a conductor. A smaller ensemble might simply repeatedly rehearse the timing changes that they want so these can be memorised but they are just as likely to look closely at each other at those moments when co-ordinated time changes are needed.
Here’s an example of a classical piece that makes extensive use of rubato:
If you put an automated drum track behind that, you’d soon realise how much the tempo is shifting and how pointless the drum track would be.
Since the 1970s, more and more music has been assembled using digital audio workstations and employs a strict tempo from beginning to end of a piece. There might be occasional shifts in tempo, but these are awkward to program and will often be avoided unless really necessary, perhaps for something like an ending.
The most obvious example of music that employs a strict tempo is dance music. Compare this dance music from 1977 to the Chopin:
So, if more and more music is robotic in terms of timing, does this mean the end of rubato, of expressiveness and individuality? Well, it certainly acts as a major constraint, particularly when the music is entirely instrumental, but it’s not an endgame.
Why? Firstly, because lots of music is still performed in the old-fashioned way (jazz, rock, folk and classical will always be like that), but also because, even when music does employ a strict tempo (including most pop and hip-hop), there is still room for a great deal of interpretation by the vocalist.
A singer will typically be guided by a click track but they can freely work around this. They can’t change the overall tempo of the underlying backing track but they can freely speed up and slow down, go ahead of the beat or drop behind it, as long as they re-join the regular beat after. Here’s a typical pop example from Taylor Swift:
OK, so this isn’t as expressive as a solo instrumentalist or a singer performing alone on piano or guitar but it’s still not emotion-free, otherwise we wouldn’t buy it. And if you’re primary interest is in dancing, then rubato’s just a pain in the arse.