Answer:
At the performance tonight, I am going to perform a jazz piece that I choreographed myself.
Explanation:
The word that is missing is an intensive pronoun (One that is used to emphasize a noun or pronoun) that refers to the personal pronoun "I".
There are eight intensive pronouns: herself (she), himself (he), itself (it), ourselves (we), yourselves (you), yourself (you), themselves (they) and myself (I). From all of those, only "myself" refers to "I", so the word missing is "myself"
