Selling music online will no doubt change the face of the music industry. You can customise your own CDs and MP3s. We will shortly be able to walk into a music store and have a compilation made to measure. With wireless technology people can download songs onto their mobile phones.
However, not all recorded music is available online. Lyrics may belong to one artist or company and the music rights to another and digital rights management agreement may be hard to reach. You will not find all your favourites on the net but there is enough music there to keep you occupied and the cost is fairly competitive.