The Voice: Louder on Two - Alasdair Malloy with will.i.am

In the run up to the 2014 Final of The Voice Alasdair Malloy took his glass harmonica on the show and played a medley he put together of 4 pieces - 1 made famous each of the judges - which will.i.am had to identify.
Presenter Zoe Ball reveals the answers afterwards.