Definitely a genre in its own right, the musical encompasses many aspects of the performing arts.
Musicals often present the audience with a fantastical look at an otherwise ordinary situation.
As with any play, novel or story, the plot can be on a variety of subjects from the 'love story' to the 'hero versus villain' to a 'look into the lives of a certain group of people'. Songs are usually an extension of the characters and often replace dialogue. And of course, one can't have songs without dancing. Make-up and hair styles also go hand in hand with the costumes to create a believable character. These are the main designations that make up a musical.