Arguably more than any other subject in the national curriculum, music is the one that undergoes the most marked evolution through the key stages. This is entirely due to two important facts. Firstly, music is a highly specialist subject that research suggests is usually the product of external social, cultural and economic factors such as whether or not the child is subject to music at home and whether or not the child is from a financial background that is able to offer the support to buy the essential equipment and tuition that is so essential to the ultimate success or failure of any given musician. Secondly, and because of this first factor, the size of the class generally becomes discernibly smaller as the key stages progress so that, by key stage four, the number of students taking music is far lower than, for instance, the number of students taking French or science. This necessarily and clearly impacts upon the attainment levels of music students as they make their way through the key stages of the national curriculum.The attainment levels are divided into eight clear and concise levels of difficulty. For key stage one, children are expected to be able to display music skills ranging from level one to level three and to attain an average of level two by the end of this key stage. As it is to be expected, this is a very basic level for children of this age, involving the use of sounds and melody through singing, chanting and speaking at different tones. Key stage one can therefore be seen as essential grounding for the more complex key stages that come later on.