Never quite put it this into words: art movements are best defined/seperated by their themes. Most high art these days takes its themes from French Philosophy. The Spectacle, Simulacra, Hyperreality, etc. In the eighties, there was a lot of huffing and puffing about Race and Gender. (There still is, but there is less of it, I think), also filtered through French postructuralist ideas about Deconstruction, bricolage, etc. In the 60's up to the 80s there was a lot of conceptual art that took it's cues from language philosophy. Surrealism took a lot of cues from Freud, and so on.
In spite of occasional historical intersections between high-art and pop-art (EG when it seemed that collage, William Burroughs and hip-hop were all on the same page, it is more likely that they do not intersect. Electric guitarists generally think about sound texture and more or less take diatonic harmony as a given, in direct contrast to the early Serialist composers, who were all about destroying diatonic harmony, and took the timbres of acoustic instruments as a given. It is more the natural state of things for there to be many islands.
Archipelagos. Islands of themes and isolated histories. As I said, Museum-based High Art these days is most often about themes elucidated by French philosophers, a set that includes Guy deBord, Foucault, Beaudrillard, Derrida, Deleuze and Guattari, among others, as elements.
However, there are other islands. In particular, there appears to be a kind of pop-art that takes its cue from the large, vulgar, playful, antiminimalist playground aesthetic that marks the stuff made in the Burning Man festival.
Then there is the new media stuff. While there are islands where media art is underpinned by French ideas, there are probably just as many that aren't. Nor should they be. The French-drenched stuff is the most rarefied and respectable, backed by the guns of the art establishment, suffused with an otherworldly glamour that is is perpetuated both by the obscurity of the ideas and the turgidity of the writing that cradles them. The obscurity of the meanings is like a mist that glamorizes a distant view. But technology can spawn its own themes.
Admittedly, not all of these themes are going to remain exciting/fruitful. For a while, a lot of media works pivoted on juxtaposing real and virtual objects. Ants mingling with virtual ants.
Empty rooms filled with information that could only be accessed using special machines that acted as "windows" into the virtual world that coexisted with the physical emptiness. One could describe this art as efforts energized by a sense of being scandalized by the idea of the virtual. This sense of scandal is probably growing weaker by the day, making it less and less likely that art will be made in its name. An early death for a shallow theme.