Let's say that listening to music is like Baking a cake. First you have to get the igredients so you go to the nearest "last.fm" store and get them. You see the Arctic Monkeys eggs and put them into your cart, because you know they are essential to prepare your cake. As you stroll around the shop you also grab Muse milk, Franz Ferdinand sugar, Oasis flour, The Strokes baking powder and they all