listened to can be an interesting experience – but now the relationship between the four tracks is no longer static. for the first time, a single person can control the volume levels of all four cds as it plays. and for the first time the result can be listened with headphones. we encourage you to play with the levels as you listen. turn one of the four levels up all the way at the start of a song and down at the end, for example. or experiment by taking one sound source out of the mix completely, or combine just two of the tracks, or listen to one at full 