I'm trying to write it out/explain in words to someone but can't do it for the life of me.
Don't use just words. If you can't illustrate what hemiola is (perhaps because the person receiving the illustration can't read music well enough), then play an example. Trying to teach music without concrete examples is an exercise in frustration, as I'm sure you're finding; with examples, verbal explanations become a snap.– user16935Oct 23, 2016 at 6:23
Don't explain. Teach them a simple dance triple meter, e.g. a slow sarabande. Then play a piece with a hemiolic ending. The fact that you have to adjust your step briefly is the hemiole. Much better than trying to explain with words which can only refer to other words that they don't know either.– Kilian FothOct 23, 2016 at 11:26
Demonstrate it and explain it- it's not that complicated.
Best demonstration: "America" from West Side Story:
Explanation: six beats can be arranged two groups of three or three groups of two. A hemiola is the appearance of one of these rhythms within a rhythm of the other.
123 123 12 12 12! Great example and easy to count along to, draw on a piece of paper etc.– Some_GuyNov 24, 2017 at 18:10
Hemiola is 3 in the time of 2, usually where 3 is in duple units (e.g., 3/4 time) and 2 is in dotted units (e.g., 6/8). No need to write it out - it was practically a mannerism with Brahms. Here is an example (note in particular the passage starting at m. 13):
2I've never heard of a hemiola & my reading skills are let's politely call 'basic'. Would I be a million miles out if I called that a 'shuffle'?– TetsujinOct 23, 2016 at 8:45
@Tetsujin, not really that. Here's the work being played along with the score. When the second screen of the score comes up, the 2nd system of the 3 that are showing has the hemiola, and the sound of it is quite distinctive: youtube.com/watch?v=p4xxgGEzzqU– user16935Oct 23, 2016 at 9:44
I should say "starts the hemiola" - there are 3 bars of it, and then another bar just before the double bar in that 2nd screen (and there is more later in the piece).– user16935Oct 23, 2016 at 9:49
A hemiola is suddenly going to half speed when the normal rhythm (which can even continue in other instruments at the same time) has an odd number of beats, so at the end of the hemiola the music is again aligned with the "proper" rhythm.
"hemi" is Greek for "half", so like "triole" means "fit three instead of what you'd do otherwise", "hemiola" means "fit half instead of what you'd do otherwise". Since music notation can readily represent halved speed (but not split into three), there is no special notation necessary for a hemiola but one still uses the name for the phenomenon.
4Nope. Hemiola means literally "half again as much", i.e., 1.5 times something, or, rounding to whole numbers, a ratio of 3 to 2.– user16935Oct 25, 2016 at 1:45
2What Patrx2 said. There is no "half speed" involved in a hemiola. Oct 25, 2016 at 7:57