do you have any go-to mechanisms for variations? do you ever think "I'm using C as a root for this theme, so let me figure out how to make a consonant call/response in F, or modulate to C# for a juxtoposed breakdown/bridge"? I find slower material can avoid sounding monotonous riding on a single root/chord, as long as there is some melodic movement. I've been trying to be mindful of chord shapes where you can change one or two notes and get a chord changes/inversions, without having it feel like an obvious change (like when a guitarist uses barre chords to go from a C to an F.
my comments are based on my understanding of classical forms . . .
afaik, the key changing is not literally a variation. a lot of times it could be changing from major to minor, or vice versa (or doing a different mode still based on the same root).
most of the time it's using the "skeleton" of the theme and then doing things to it. say you have a melody in quarter notes (C-E-D#-G) and you do it as triplets (C[C-C]-E[E-E]-D#[D#-D#]-G[G-G]); (keeping the triplets) sometimes it would be doing the melody with filigree (C[B-C]-E[F#-E]-D#-G[Ab-G]). it can also be elongation—A/A prime sort of stuff (C[B-C]-E[F#-E]-D#-G[Ab-G] + (C[B-C]-E[F#-E]-D#-G[Ab-G]-F-F#[F#-F#]-E[D#-D#]).
you could also take a busy melody and take it down to its highlights (C[B-C]-E[F#-E]-D#-G[Ab-G]-F-F#[F#-F#]-E[D#-D#]) becomes (C-E-G-F-D#) in long tones/rhythmically placed in the same timeframe (things that would be repeated quarters becomes halves or dotted halves)
augmentation (make the quarters above into halves—twice as slow) and diminution (quarters become eighths‚twice as fast) are also good
Do you find yourself writing in variations of 4/8/16 bar sections? I find myself writing in 5/4 time to break away from the familiar 4/4 feel, even if it isn't the most natural sounding thing I could do.
yeah, it's hard to break away from that sort of thing, particularly in any sort of groove music. i like to break away from the 1. but i also will add a 2-bar phrase in at times.
I also find the Rule Of 3 pops up in my writing. I really gravitate to having three sections, or three variations on a theme, or some other use of three in the underlying architecture of the composition.
contrast is good. proportion is also super important. three sections is sort of verse/chorus/bridge, of course (so is sonata form). (nothing wrong with that, it's time-honored.)