In this article the highly contested relationship between art and politics in the twentieth century is discussed by way of the life and work of the Portuguese composer Fernando Lopes-Graça (1906–94). Lopes-Graça, who described himself as ‘a communist from birth’, lived for almost fifty years in Salazar's ‘New State’, a Fascist-type dictatorship, which emerged from a military putsch in 1926 and lasted until 1974. His experience as a communist under a right-wing régime was therefore very different from that of either communist composers living in Western democratic countries or those active in the Eastern bloc. Lopes-Graça stood apart from most other party intellectuals in his resistance to the doctrine of socialist realism. Yet from 1945 onwards he composed revolutionary songs in which his communist engagement is directly evident. Understanding this apparent tension within his output requires both a careful and nuanced understanding of his own personal position and a clear distinction between political engagement in music on the one hand and socialist realist or neo-realist tendencies on the other. It is that latter distinction – between (in the composer's own terms) ‘lived action’ and ‘imagined action’ – that accounts for the seemingly contradictory coexistence in Lopes-Graça's thinking of aesthetic autonomy and political commitment, and in his music of (to adopt categories posited by Heinrich Besseler) both ‘presentational’ music (for conventional concert settings) and ‘colloquial’ music (to be sung and played ad libitum in political meetings, at demonstrations, in the home, or even in political prisons).