Symphonies don't necessarily have to be performed by a large orchestra. Classical era symphonies (such as symphonies by Mozart or Haydn) are typically performed with smaller orchestras.
Yes, I thought that question was a bit vague, though as it's quite hard to define a symphony I don't know what other clues they could use. Maybe "Beethoven wrote 9 of them"?
He also reads from "sheet music", which is what I got so fixated on I was never going to come up with "score" (although I too tried "stand" in desperation).
The conductor specifically reads from the score, which is the master "sheet music" on which all of the parts are included. That way, the conductor can see each instrument's part while conducting, allowing them to cue instruments throughout the song.
Never heard of the selena in this clue, I knew chandelier, but only knew the name of the artist from a quiz i took yesterday (maybe the c quiz? can't remember)
I had just got done posting a song on facebook by a lesser know band Shonen Knife, so when I saw this quiz I thought maybe? Oh well, give them a listen, folks.
(Don't ask, it came from a Stevie T video)