I think, listening music is like to read.
You can't read and do another thing on the same time.
So if you REALLY want to listen, it is impossible to do something during you are listening.
I think lot of people are listening music in the train, in the street, at work, just to make a "wall" between them and the other things. To isolate themselves.
This is not listening music, this is just create a separation between the world and the listener.
When I go to a classical concert, I will not take my computer with me to work, and even sometimes when I go, if I am worry about something and thinking during the concert, I am not listening music, music is just there to help me to think.
So music can help to make lot of things, but if you want just to listen in the pure respect of the art, you have just to sit down, relax and concentrate yourself on the music.