8- or 16-bar themes

Apologies if this is a really basic question, but it is very non-obvious to me because I'm a mostly-self-taught amateur composer... I've been noticing on various composition resources out there that people keep referring to 8-bar or 16-bar "complete" melodies or themes. Why 8 bars or 16 bars specifically, as opposed to, say, 6 bars or 13 bars?

The thing is, in most of my compositions I rarely have 8- or 16-bar themes. I find myself having 5-bar melodies, which lead to 9-bar / 10-bar themes, or 6-bar themes, or 3-bar motifs that lead to 6-bar/9-bar themes, etc.. Is this normal??

Also, I find that my compositions often have "run-on sentences", so to speak, where a 5-bar motif has its final notes in common with the opening notes of the subsequent motif, so the result is 1 bar "shorter" than it "should" be, if they have had no notes in common. Is this normal, or is it a sign of some kind of deep structural defect in my music?

Do these "odd-length" melodies/themes have any longer term structural implications, besides their "unusual" length? Are they an actual issue I should be aware of, or am I over-thinking music theory here?

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  • Hi H.S.,

    In general, there can be great advantage if you understand why melodies tend to be done in multiples of 2, 3, or 4 and why melody structures tend to be 4 or 8 or 16 bars, even if you don't use these structures. These are very satisfying to the listener because they fit in with everything they have heard before and are used by most popular music, and also are simple and satisfying. But there is no rule saying you can't compose anything outside of those bounds. The only rule really, is *don't suck* - rules of meter and melody length are not what composition is about. Composition is about having a good melody, good harmony, having coherence in the piece from beginning to end, return, advancement, climax, and denouement, and of course, a kick-ass ending.

  • Thanks for the response! Yes, I know I can compose outside those bounds, and I have done so. I think the result still sounds OK. Or perhaps I should post samples for people to critique?

    What I'm more concerned about, though, is the worry that perhaps I *don't* understand melody structures, and therefore am not composing as effectively as I could be. Are there any good online resources that explain the concepts behind it?

  • If you think about and you acknowledge the fact that melody as we appreciate it in western traditions started off and walked hand in hand with poetry for millennia, then you must think that the length of melodies is very strongly depended on the length, quality and variety of poetic feet (briefly: durations of stressed or unstressed syllables contained in poetic feet). We as humans seem to have an inherent aesthetic need for symmetry and this need has resulted in our melodies tending to be symmetrical and even, but this symmetry is more obvious and pronounced in even cycles of 2, 3, and 4 as Gav points out.

    This is not to say that symmetry does not exist in odd lengths of 7, 9, 11, 13, etc. It is there but in my opinion it tends to be rather less obvious and perhaps of a higher aesthetic order.

    So, the best course of action that I would suggest is to familiarize ourselves well with tradition first and its simpler forms, before proceeding to more complex and "higher" combinations.

  • Yes

    H. S. Teoh said:

    perhaps I should post samples for people to critique?

    8- or 16-bar themes
    Apologies if this is a really basic question, but it is very non-obvious to me because I'm a mostly-self-taught amateur composer... I've been noticin…
  • OK, I posted one of my pieces in the critique and analysis section: sonatina in E-flat major, which has a 5-bar melody structure in the first subject and a second subject built from 3-bar phrases. Let me know what you think. :)

    Sonatina in E-flat major
    Here's a sonatina for solo piano that I wrote back in December 2000, which I recently dusted off the shelf (figuratively speaking), touched up a litt…

    The Symphony in Eight Seconds has its main theme contained in only one bar, I believe. I speak of a theme, as you do, and not of a "melody." There is a strict science of composition and modern music theory that states "no theme should be longer than the movement in which it is contained," which makes sense from the purely mathematical point of view. Infinitely long themes are allowed, but only inside of a composition without any temporal limits whatsoever, such as the Symphonietshcht Infinitatum Alep-12 in Mu Flat Major, or in a work like the Cantata with No First or Last Note.


    It might be best to start out with something infinite (or nearly infinite) and then just pare it down to a few nanoseconds. Much may depend on how many beats per minute you want to see pass as the work unfolds.  If the composition is played on the piano, then a finite amount of time must pass between the movement of one finger from the first key to the next; if the work is played upon the frets of the mind, then the limits are defined in a different way.



  • I have this little fugue by Bach which illustrates starting the next phrase on the last bar of the previous so (kind of) seven bar phrases.


  • Hmm, that file showed up all wrong for me (wrong / missing fonts perhaps?), I only see note stems and some out-of-place floating note heads and clefs. Can't make any sense of it. :-(

  • P.S. Found a readable score (arrangement for brass quartet). Don't worry about it, thanks!

  • The universe functions on the mathematical square. So does composition!
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