I've always been a believer in the "power" of song, that one can render a controversial message more palatable, either via jaw-dropping ivory-tickling or funny bone tickling, or both. Case in point: Justin Timberlake as Elton John reworking "Candle in the Wind" on behalf of the late Hugo Chavez. The only thing missing was a Gibb brother cameo.
In another instance, a live performance can be transformative, transport either the lead singer or the soloist (again, or both) to a place where he or she can shine in such a way that they take the audience with them, where ego and envy dissipate, simply unable to compete with melody and musicianship. Case in point: A college student asks his idol, Billy Joel, if he can accompany him on his favorite song, "New York State of Mind."
Both clips are wholly entertaining and inspiring, and in two totally different ways. As for the latter, many folks are saying the student "stole Billy Joel's thunder." I would contend it was happily lent to the lad.