If you are interested in studying the concept of multiplicity in Deleuze and Guattari, in particular in the context of art, I recommend this volume. I have a chapter in it (draft here) but the recommendation is for the many other important chapters where leaders in the field have done new and important work.
Deleuze, Guattari and the Art of Multiplicity
Edited by Radek Przedpełski, S. E. Wilmer
