Some people think the really great invention is not just tool or machine, it should be lasting for ever as a classic such as music. In the dinner, book store, department store and so on, the musci is everywhere in our life. Maybe the cellphone or computer change some habits we used to, but the music can change something more precious.
Now, most people used to listening to the music when taking a bus, MRT or walking. If you find a great song and try to share with friends, you would need a speaker and audio cable; it would be much better than passing the ear phone on by one, right?
The developement would nerver stop when the requirement exists. When you realy like the music so much, then you might be willing to pay for quality. Actually, the best music you can hear is the live, any tapes, CD and mp3 would loss part of the sound wave after processing. Via the specific audio cable, you can enjoy the sound just like you are there; of course, it takes prices as well.