Conversation so far:
how did Vaslav Nijinsdky's career start?
Vaslav Nijinsky danced in the Mariinsky production of Mozart's Don Giovanni, in a ballet sequence choreographed by Michel Fokine.
what did Vaslav Nijinsky  do after he danced in the Mariinsky production of Mozart's Don Giovanni, in a ballet sequence choreographed by Michel Fokine.t?
Vaslav Nijinsky performed at Krasnoe Selo in a makeshift theatre. These performances included members of the Imperial family and other nobility, whose support and interest were essential to a career

Question: why were they essential?
Self-contained rewrite: why were these performances that included members of the Imperial family and other nobility, whose support and interest essential for Vaslav Nijinsky?