It would be impossible to cover the entire 30+ career of Elton John in just 18 questions; so maybe I'll do an Elton John II sometime.

1. What is Elton John's real name?
2. Who was Elton's main songwriting partner?
3. What was Elton's first big U.S. hit, in 1971?
4. Who "was born a pauper to a pawn on a Christmas day, when the New York Times said God is dead"?
5. Who had "better get back to the woods?"
6. What '50s throwback song was Elton's first Number 1 hit in the U.S.?
7. What country was Daniel headed for?
8. Who wears "electric boots" and "a mohair suit?":
9. Elton sang backup, uncredited, on a John Lennon song that hit Number 1. What song was it?
10. In 1975, Elton had a hit with a remake of a Beatles song. What song was it? 
11. What American city's "freedom" did Elton salute in 1975?
12. What did Elton say in a "Rolling Stone" article in 1976, that surprised some people but not others?
13. Elton was chairman of a sports team in Watford, England for a while. What sport did the team play?
14. Elton was one of four artists who sang on the AIDS charity single "That's What Friends are For" in 1985. Who were the other three?
15. What distinction does "Sacrifice" have in the U.K.?
16. Elton wrote the music for what Disney animated movie in 1994?
17. What song did Elton perform (with re-written lyrics) at Princess Diana's funeral?

Bonus: Elton's 2001 video, "I Need Love," consists of a prominent actor walking around a house and lip-synching the lyrics. Who is the actor?