The Sociology of Education has undergone a far-reaching change of emphasis. The prime concerns of the 1950s and 1960s, input-output studies focusing on the interrelationships between the educational system and the stratification system, have given way to a more explicit recognition of the social and political nature of education. A major influence has been the development of the 'music appreciation' movement; this was associated particularly with the writings of Stewart Macpherson and Percy Scholes in the 1920s and 1930s. Sociologists working within the theoretical perspective of the New Sociology of Education have sometimes been criticised for overemphasising the possibilities for change in teachers redefining their situation with alternative definitions of knowledge, ability. The reorganisation of secondary schools with the Education Act of 1944 resulted in an increase in the specialist teaching of music in schools and an acceptance of the principle of general music classes for all.