Musical Theatre is a combination of singing and acting. So for G7 I had to do 4 songs from shows of different eras, plus act a libretto extract related to one of the songs, plus a viva about the songs, the shows they came from, the composers/librettists, etc. For G8 I will also have to do an acting sight read. The number of songs required increases and the dates required get more specific as you go up through the grades and the libretto extract doesn't come in until G7, but right from the start the way the songs are acted as well as sung is taken into consideration. They like the song to be choreographed and some indication of costume and props as well.
This time, I did When Frederick Was a Little Lad from Pirates of Penzance, Can't Help Lovin' Dat Man from Show Boat, I Hate Men from Kiss Me Kate (with libretto extract) and When You're Good to Mama from Chicago.
I hope this isn't too much information!