broadwayworld.com

R5Vl1 TIL in the musical Phantom of the Opera the title character is only onstage for 27 minutes and his co-star, Christine Daae, is on stage for 2.5 hours. Yet the Phantom is considered the lead.
p8Jn4 TIL about Rachele Gilmore, an understudy in the Metropolitan Opera. With only a couple hours notice, she was told she would be making her debut in Offenbach's "Les Contes Hoffman". That night she hit an A-flat above high C, breaking the record for highest note ever sung at the Met.