Scene 1 - 'Main Titles'
The movie starts off from the perspective of a theatre, beginning in pitch black, with a bit of chatter, which would be the same as if you went into a real theatre, the sound of everyone calming down and getting themselves comfortable, then as the lights come on the live orchestra starts.
The conductor I feel is added for a bit of comedy, to contrast with the beginning sadness of the introduction.
The twentieth century fox logo, which everyone is accustomed to seeing, is noticed again as Bazz Luhrmann has given the introduction and opening credits an olden day feel, simulating the scratching you get on the old films.
After the 20th century fox logo, when the movies actual opening credits begin, the music chosen is three different songs, which are "The sound of music", ???? and "The CanCan" to give a (can't think of the word, it means example of the songs shown) of a few of the songs used in the movie.
The fast tempo acceleration of The CanCan music with the silhouette of a can can dancer in the background gives the image a exciting element, which cuts sharply to the silent old fashioned footage of the title "Paris 1900" to give the audience a refrence point.
Scene 2 - 'There Was A Boy...'
The camera zooms in onto the screen, cropping the theatre stage and the conductor, implying that it's serious stuff now, and not fun and games.
The scene first shown is of Christians apartment, with the L'amour sign shown prominently, revealing to the French-speaking audience that the movie is about love, on the left of the apartment is Toulouse-Lautrec (John Lequizamo) singing Nature boy (written by Eden Ahbez), when he starts singing about 'a very strange and enchanted...