We’ve already laid out how music generally subdivides each count into 2s or 3s. This means that in 4/4 (or 3/4 or 5/4 or 6/4 or 213/4) time the first duple subdivision results in a 1/8th note, and the next a 1/6th note. We can keep subdividing by 2s and reach 1/32nd notes and I’ve even see 1/64th notes in print. This can keep going to 1/124th notes, 256th note, 512th note and even 1024th notes, and in theory could continue.
If we were subdividing by 3s, an “eighth note triplet” figure with three notes takes the same amount of time as an “eighth note duple” with two notes. And three sixteenth note triplets takes the same amount of time as two regular duple sixteenth notes
The kind of subdividing going on in a song is something to listen for, no matter who you are in the band. Generally, if the song has an eighth note feel, or a sixteenth note feel, everyone is playing to that level of subdivision, and no one instrument is exceeding that. For instance it would be very unusual for a song with an eighth note feel to have sixteenth note tom fills, or riffs with sixteenth notes in them.
The possible exception to this (and something which I love) is the use of 16th-note triplets in the hi-hats in a song with an eighth note feel. For some reason the triplet used against the duple doesn’t mess with the overall feel of the song, and can really add a wonderful freshness or urgency. Michael W. Smith’s “Goin’ Thru The Motions” is one notable (old school) example of sixteenth note triplets in the hi-hats in a song with an otherwise eighth note feel.