I'm not sure if what I mean has an actual name, but I'm currently playing a piece (Chopin's Op. 20, Nocturne in C-sharp minor) which has several sections analogous to this:

Fragment of Chopin's Nocturne with septuplets in one hand against 8th in the other hand.

That is, some tuplet in the right hand and 8th notes in the left. The specific note lengths are irrelevant for my question; the problem is that they don't match in the sense that the number of right hand notes isn't divisible by the number of left hand notes. I.e. in my example there's 3.5 notes for every 2 in the left hand.

I'm having trouble playing these two melodies together. What I can play without major problems is a triplet in the right with two 8th notes in the left hand but anything more complicated than that won't work.

My piano teacher basically suggested not to try and play it "mathematically correct" which makes sense to me since you'd probably go insane trying that with more complicated examples. However, I still have trouble playing both lines together. Are there any techniques for practicing this?

I'm aware of the Question How can I significantly improve my hand independence on piano? but it doesn't answer my question as the answers (and question) assume a "matching" number of notes in each hand.

  • 3
    I disagree with vtc. Triplets are commonplace, and their timing is pretty straightforward against a straight beat. 14 against 4 is a rather different, and difficult kettle of fish, and answers could be specific to that.
    – Tim
    Commented Jun 2 at 14:44
  • 1
    @Aaron If you believe the questions are duplicate, cast a duplicate vote. Commented Jun 2 at 15:56
  • 1
    @Aaron I see. To me, the three questions are related, but are asking about different aspects. One is about playing a single line triplets (in the context of a different music style), another about playing polyrhythms in fast tempo, and this one is about learning to play polyrythms at all. Also, if you believe the trick you suggested for 18:4 would work the same well for 14:4, it would be worth writing an answer, as it's not obvious to me. Commented Jun 2 at 18:15
  • 1
    A canonical guide to odd rhythms seems like a great asset, SE isn't set up so much for that from what I've seen. This particular question is not so different from half-note triplets, or as I would say 2 against 3 rhythms. In principal, there's no limit to questions here: 3 against 5, 3 against 7, 3 against 8, 3 against 11, 3 against 13 ... repeat with 4, repeat with 5 ... literal infinite possibilities for questions here that are all fundamentally the same.
    – user121330
    Commented Jun 2 at 22:31
  • 1
    N.b. among many complex rhythms in Op. 20 there are no septuplets. The example in this post is made up. Commented Jun 3 at 13:50

4 Answers 4


Chopin often writes combinations that are obviously not intended to be worked out mathematically, because it would be ridiculously difficult to play them correctly, and it wouldn't even sound good if you did. The ones that he does intend to be mathematically correct are only (in my experience) the straightforward examples of two-against-three and three-against-four.

In general, when Chopin writes a number like your example, he is saying "please do what I mean, I hope you understand".

  • 3
    At last a sensible answer. One practice help is to concentrate on beats: practice playing 7 notes in the right hand, and feeling it as a unit, then two notes in the left hand as a unit, then play the units together (see "hand independence") Commented Jun 3 at 9:15
  • 3
    I have only one piece to add to the discussion, so maybe I'll suggest that you edit it into your answer if you agree: Learning to play the septuplets with precise rhythmic equality may a useful initial learning step, but it's surely not the desired final result. "Metronomic" is usually an insult in Romantic repertoire, and it's especially out of place in a Chopin right hand. True, it's helpful to understand and internalize the underlying rhythm, but after doing so, you'd want to liberate the figures to ebb and flow organically. Commented Jun 3 at 22:59
  • This kind of looseness is found in some Baroque keyboard music, running scales and arpeggios that are meant to sound like an improvisation. Commented Jun 4 at 15:05

I would suggest to try to play it "mathematically correct" as the first step.

Often the best method to practice simultaneous rhythms is by learning them linearly. See the example below.

  1. Play the septuplet alone.
  2. Replace the fourth note (D) with two notes of twice shorter duration.
  3. Realize that the extra note is played at the same time as the second note in the left hand.
  4. Remove the extra note. Practice.

Slow down tempo as needed, and gradually speed up. You may also tap the rhythms on the table with two hands, rather than playing the actual notes.

Once you can play the sequence fluently, focus on listening to the right hand only, then left hand only. This is a good starting point to let the rhythm flow naturally.

enter image description here


Tuplets in one hand don't often match up to what's played with the other. Best method to practise is to use a metronome. This could be set for the two crotchets in the l.h., which would give you the half-way point in the bar, so timing 7 to each click. or you could click for each quaver, and practise until you manage to get all seven semis in each two clicks.

There's also the possibility - slowly, of treating the whole thing like adding fractions with different denominators - set the metronome to say, 14 (common denominator), very slow, so could set at 140, or any number that's a multiple of that 14, and play along so that you're aware which clicks are for quavers, which are for semis. With two metronomes, you could actually hear what it all sounds like!

L.h.? Well, that's probably chuntering on like it did in previous bars, so when the r.h. is regular, it should be relatively easy to fit it all together. Good luck!


On this example, an easier method is actually described by the kerning of the notes. Notice the space between the first group of 4 and then the group of 3 in the 7-tuple. There are 3 requirements for accurate rhythm here:

  1. The first of 7 must occur with the "on" eighth note
  2. The "off" eighth note must occur dead center between the 4th and 5th 7-tuple
  3. The 7-tuples must all have the same duration

That's it.

To answer your more general question would require a bit more work, but start with this answer for your standard A against B rhythms where A and B aren't prime numbers over 5. After that, you'll have to get slightly clever with fractions to figure out where a note gets placed. If this had been 3 against 7, you'd need imagine micro-triplets inside each 7-tuplets and then insert the triplet-eighth notes on the second and third micro-triplet respectively after 7-tuples 2 and 4. At some stage (or with enough tempo), it starts making sense to treat them as grace notes and let the precision go. We aren't computers.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.