That's the fun thing about mediums; they're subjective. Every sense has different capabilities and spaces within which exploration and originality can occur. Traditional art is constrained to a canvas or medium, while music is confined to the audible spectrum of frequencies, the air around us, and our ears.
With that being said, "geometry" in music may occur in several different ways. "perspective" may depend on who you ask, but this has much to do with the stereo field and frequency content or phasing of a particular sound. I think Bartók may be the best example if you're to draw a line to Cubism, as is harmonically and technically complex music as a whole; but associations are clear with Bartók. Be this the time period, a direct influence, or just causality - Maybe a better way to represent cubism is with simplicity. One could compose using basic counterpoint and polytonality, and evolve motives and ideas using polyrhythms and chromaticism. Modulation is helpful for adding dimension, as negative space may do in a painting.
I believe the quote "Music is just sound, arranged" is attributed to John Cage, some of whose works may also fit the bill. Music is built from silence, and is typically thought of as an additive science. Artists have solvents and can remove layers of paint with them or chisel away; recordings fell short of this liberty until the advent of editing software took the pain away from messing with tape.
I would utilize silence in a piece to represent cubism. Not in a 4'33" sense, but I'd make the point that I'm not afraid to build tension with nothingness. If we look at Picasso's "The Reservoir" we see well-defined structures that abstract the plane they're on. If you belay thought to a topological plane, you may be able to think of this as a piece of paper with certain points lifted, and skewing the perspective to create space, boundary, and perspective. In my mind? That's the painting. I would achieve this in Atmos sound, or the most vivid surround sound I can get my hands on. Utilizing data processing techniques like Ryoji Ikeda, I'd immerse a listener in pure tones and filtered noise, and not be afraid to mangle traditional instruments to create granular tones which evolve, morph, and drive their harmonic content in inventive ways that aren't achievable by playing said instruments. If we jump back to the composition techniques I listed earlier, their particular combinations might be powerful with a listener's eyes closed. I would craft an experience using stereo panning to make them feel like they're being enveloped in familiar, yet alien textures that are moving.
I would create perspective, edit familiar sounds to create safe, explorative aural experiences, and utilize polytonality and polyrhythms with pure tones and white noise to make sure my listener gets, and keeps their goosebumps.
I highly suggest listening to Ryoji Ikeda's "Dataplex". He turned it into a full art installation which utilizes light and sound in the ways I've described. My approach to this question has drawn from my being influenced by Amon Tobin, who utilizes fringe data processing and software to create incredibly moving soundscapes. His biggest success was his album "Isam" which I highly suggest listening to on the best audio system you have available. Tracks like "goto 10" reference programming, while "Kitty Cat" utilizes foley and field recordings to create a mesmerizing, more "traditional" song.
Bartók is still the best example when you draw lines to exclusively classical art as a whole. It is my opinion that a modern interpretation is best served by not constraining yourself to a timeframe, but utilizing a modern one which is built on the old - which is why I've confided in the examples provided.