pastiche \pas-TEESH; pahs-\ (noun) - 1 : A work of art that imitates the style of some previous work. 2 : A musical, literary, or artistic composition consisting of selections from various works. 3 : A hodgepodge; an incongruous combination of different styles and ingredients.
"Johnson's work was a pastiche of dozens of styles and from the recent past and antiquity, put together in such a way to suggest something totally new and original."
Pastiche comes from Italian pasticcio, "a paste," hence "a hodgepodge, literary or musical," ultimately from Latin pasta, "paste."