I.about [美 əˈbaʊt, 英 əˈbaʊt]副about often appears as the second element of certain verb structures in English (fool about, knock about, move about, etc). For translations, see the relevant verb entry (fool, knock, move, etc)
The first phase is various singers coming forward with their audition piece while the others lounge about waiting their turn, occasionally relieving their boredom by joining in.