Diegetic an non diegetic sounds

The difference between the two types of sounds is basically diegetic sounds are recorded on set using a object or instrument non digetic sounds are sounds that are inserted off set eg soundtracks

In the star wars trailer at the start you hear a piano playing high pitched notes this continues throughout until around 1.20 then you hear the authentic star wars trumpets then near the end it goes silent and the trumpets play in a quiet pitch it is quite obvious which sounds are diegetic and none diegetic