Depends on what period we're talking about I suppose. Liszt and Xenakis...
He wrote this I believe :-
But in addition to these two modes - inferential and experimental - art exists in a third mode, one of immediate revelation, which is neither inferential nor experimental. The revelation of beauty occurs immediately, directly, to someone ignorant of art as well as to the connoisseur. This is the strength of art and, so it seems, its superiority over the sciences. Art, while living the two dimensions of inference and experimentation, possesses this third and most mysterious dimension which permits art objects to escape any aesthetic science while still enjoying the caresses of inference and experimentation.
So I think he'd hope what he created was art rather than science. He seems to state that art and science share some characteristics.
But, he seems to differentiate between experimentation being in art and science, inference being in art and science and "truth" being in art and science and any erroneous [imo] conclusions that might be drawn from that observation that art might be science or or that something might be "science" because it has experimentation / inference and "truth"
Although what he did [in the sense of what he did with the material he took influence from, rather than the whole process of his composition, which I would call art] sounds more like applied maths, to me, rather than science.
There's a song called Einstein a go go or something that has E=MC
2 in it.
That seems as influenced by science as his work is. What he seems to do that is very different from singing about Einstein is use the mathematics. Some of the same maths that is applied within science too. [Which is obviously because that's his influence rather than a coincidence, although the maths is most probably used elsewhere]
So, to me, the results could be applied maths or art and I'd favour the latter description.