Inspired by "Treble and Bass Clef Bookend by gatto_".
I made a modular bookend that utilizes square pegs to hold decorative designs. I simply extruded SVG drawings of a treble clef, eighth note, quarter note, and a quarter rest with pegs on the bottoms.
You might have to glue the pegs if the tolerances are off or want it really secure, but you could easily modify the design to create a taller peg and bookend bottom to avoid glue.
The example print had a 1.0 mm nozzle, wiggle infill, and 0 top/bottom layers on the yellow parts, then was glued into black bookends that are camouflaged by the shelf.
Do note that the tail of the eighth note won't fit on a left-sided bookend unless you reverse it.