The double scaled SYK model provides perhaps the simplest example of holography. It admits a diagrammatic expansion in chord diagrams, and these chords directly capture geometric information about the dual spacetime. Probe matter in the bulk corresponds to adding other types of chords. I will briefly review that, and then discuss deformations of the model where such matter becomes dynamical. For some deformations the bulk changes smoothly, while for others it involves a phase transition.