'Angel of Music' is a song from what Andrew Lloyd Webber musical?

Angel of Music is a song from the stage musical The Phantom of the Opera composed by Andrew Lloyd Webber. It is sung as a duet between Christine Daaé and The Phantom and is sung right after the song "Little Lotte" and right before the song "The Phantom of the Opera."

During the song, Christine is getting ready for bed when she hears the Phantom singing to her. At the start of the song, the Phantom harshly criticizes Christine's childhood sweetheart, Raoul, saying that he is riding on her success. Assuming that he is the Angel of Music, the man who has been coaching her, she sings back about how she wishes to see his face. An image of the Phantom appears singing to and hypnotising her. Christine slowly walks towards him, singing. She actually walks through the mirror of her room into the Phantom's tunnel. The song ends with the Phantom singing "I am your angel of music, come to the Angel of Music!". Raoul, expresses shock at hearing the Phantom's voice from outside Christine's dressing room, saying "Whose is that voice? Who is that in there?". Prior to this, however, Christine confides to her ballerina friend Meg Giry that an Angel of Music visits her, and they sing a duet of "Angel of Music" as well.