Art is applied imagination - visually, sculpturally, theatrically, literary, musically etc. In other words, a conscious, deliberate and most importantly human process rooted in human experience. One may engage certain tools in order to achieve a particular outcome, but the tool itself is not the creator. If someone were to accidentally drop a violin causing the strings to sound, this is not music because nobody willed it.
Of course, one may create art by involving elements of chance - in music academia, this is known as indeterminacy or aleatory. A good example is Earle Brown's graphic score
December 1952, which pushed the boundaries of composition in not assigning precise musical features such as pitch or rhythm like a traditional stave. However, he still makes creative decisions when constructing the score, such as allowing performers to determine these components, who in turn make creative decisions when interpreting it. Hypothetically, if someone
deliberately dropped the violin as part of an experimental piece, they too are making an artistic choice and it now becomes something meaningful, though whether one would describe the results as music rather sound or performance art will depend on one's definitions of all three. The crucial constituent is intentionality.
I apply the same rule to AI. It can be a tool like any other, but never the artist, because computers cannot think and feel - they respond to programming. Ergo sounds/pictures/words generated independently of human expression, whether at the composition stage or in the manner of their arrangement, are not art by definition (mine), no matter how beautiful or thought-provoking they might be on their own terms. I might notice an ancient tree, struck by its form and colour, but it does not become art until I take out my camera and subjectify it.