Write something sparse
Sometimes I write a challenge involving a specific music theory concept and sometimes I write a more vague challenge. This one is in the second camp.
The dictionary definition of sparse is "having widely spaced intervals" but that might seem too specific to music so lets define sparse this way:
Sparse music:
1. gives room for empty space
2. favors utility and simplicity over ornamentation and "extra" notes
Ways to approach this challenge (you could focus on one or two or all of these things)
Tonal sparseness:
In tonality, sparseness could mean vagueness. Like, you could barely provide enough information to figure out what key you're in. For example, the guitar could play just roots, or roots and thirds. Or if you're playing bass on your track, the bass could play roots and the guitar could just play fifths or thirds and fifths. If you're sticking to just guitar, you could think of spread out chords and only playing the minimum number of strings possible.
Rhythmic sparseness:
Instead of strumming the entire time, you could try strumming once at the beginning of the measure. Or doing something like ::root strum root root root:: where you're keeping rhythm with just the root note and occasionally (maybe once a measure?) revealing the chord. This might be a fun opportunity to mess with a pedal tone (keeping the same bass note going with different chords over the top) as well, since it keeps things sparse too.
Aesthetic Sparseness:
You are welcome to explore your own ways of being sparse, wether thats a guitar tone that feels sparse, lyrical content that feels sparse, or some other part of the song that feels sparse. If you've got other ideas, go for it!