Constructed in 1926 as part of the Orpheum vaudeville circuit, the Orpheum is an ornate Beaux Arts-style structure designed by G. Albert Lansburgh. The theatre can seat around 2,000 people and contains a Wurlitzer organ.
The two Howards watch the rehearsal from the balcony and later the two versions of Baldwin encounter one another in episode 1x02 "Birds of a Feather".
From episode 5x02 "Unlike a Virgin".
From episode 2x10 "The Abduction".
The Orpheum was used for opening of 'The Chipmunks 2007 World Tour'.
From episode 2x07 "Chuck Versus the Fat Lady".
Source: Tony Hoffarth — Flickr
From episode 3x13 "Waiting in the Wings".