In any field, not just music theory, augmentation and diminution are just words for making things bigger or smaller – you could just use the terms ‘growth’ or ‘shrinkage’.
The way we're using the terms has nothing to do with augmented or diminished chords –although you could easily be forgiven for thinking that, having read the title of this month's guide. What I'm talking about here is augmentation and diminution when applied to rhythm and melody.
Rhythmic augmentation – the lengthening of the time values of notes in a melody – can be used to imply majesty or reaching a high point, useful for an imposing finale. Rhythmic diminution, on the other hand, is the shortening
