The ballet being performed is Giselle, which in a way reflects the relationship between Marcus, Chloe, and Lucifer. Very broadly, a deceitful man leading a double life falls in love with Giselle, while another man, who also loves her, tries to persuade her the first is not what he seems - with disastrous results for all.
A tragedy-stricken production of Giselle in LA is also central to Angel 3.13 - Waiting in the Wings. The most emo of ballets, it brings nuances of its own lovelorn, supernatural story-line to the shows that reference it.
Episode title spoken by Lucifer.
Lucifer describes the 1967 Ford mustang Shelby GT500 "...zero to sixty in, well, fast."
0-60 mph in 6.1 seconds, to be exact. Fast indeed.