Augmentation (and diminution) is a kind of motivic variation.
Take a motif (or an entire phrase) and increase/decrease the duration of each note by the same proportion, e.g. double or halve the length of every note.
Strict augmentation is doubling/havling the lengths.
You can apply this operation by a factor of 3, 4, 5… to the idea but it may become unrecognizable because it takes too long to play out, or simply be too quick. A factor of 3, 5, 6, 7 or other similar numbers may require the meter to be changed, too.
belkin-2018 (p.6 par.1) considers it to be a “distant form” variation.
Examples
