Subdivisions

A subdivision is when you divide a specific note up into smaller notes, which when added all together, equal the length of there original note. For example, a semi-quaver is a subdivision of a quaver, because the semi-quaver is half the length of the quaver, and a demisemiquaver is a subdivision of a crotchet, because the demisemiquaver is an 1/8 of the length of a crotchet. There are different ways of representing subdivisions in written music, depending on what the subdivision is. Straight subdivisions are written using normal notation, because in normal notation, which is the series of note lengths from breves to hemidemisemiquavers, each note is half the length of the previous one, so these count as subdivisions any, and are referred to as straight subdivisions.

So, these are all normal notes, but are also subdivisions.
   

Subdivisions which are not straight, as in notes which don't fit into other normal notes, like the ones above, by systematically halving them, are represented in written music in a different way. If, for example, there is a subdivision of five, meaning a specific note is split into five evenly spaced notes, then this would be represented by either joining all of the notes within that subdivision by one of the horizontal lines that normally join notes (technically known as a beam), with a number '5' written above/below it, or, all of the notes within that subdivision would be encompassed by a cap-like sign above/below it, again with a number '5' written above/below it. So, whatever the subdivision is, other than normal, straight subdivisions, all the notes within it will either be joined by a normal line, encompassed by a cap sign, or perhaps with the use of both, depending on the rhythm of the notes and the note values within the subdivision, where some notes would be connected with lines, with rests between other notes, but which are all part of the subdivision, and so would still all be covered by the cap sign, and then, finally, the number representing the subdivision (representing how many evenly spaced notes the original note is split into) would be written above/below the notes, and possibly above/below the cap sign too, if there is one.

Here are examples of what these kinds of subdivisions look like:





You can also get subdivisions which are written with two cap signs encompassing the notes of the subdivision, one over the other. This is basically a subdivision of a subdivision, which is based on the use of multiplication. To work out the note length of the notes within the subdivision, you have to multiply the two different numbers together, and this number will show how many evenly spaced notes the original note of the subdivision is split into.

There is another kind of subdivision where a group of multiple notes can be subdivided, instead of just one single note being subdivided. This is written by having two numbers with a colon sign between them, which represent the subdivision, placed where the other normal subdivision numbers are written (above/below the beam or cap containing the notes of the subdivision). The first of the two numbers (the one on the left of the colon) shows how many evenly spaced notes the overall group of notes is split into, and the second number (the one on the right of the colon) shows how many notes are put together, to then be subdivided as one. The note values of the notes put together to be subdivided are not included in the subdivision sign, but you can work out what these note values are, by looking at what the note values of the notes within the subdivision are, and after working out what the evenly spaced note value is, which will be clear, from adding the notes of the subdivision together, this note value will be the note value of those notes added together to be subdivided.

Another consideration to make with subdivisions, is that they can cross over bar lines, so you could have a subdivision which covers parts of two individual bars.