Sentence:  Nevertheless , Prokofieff was much influenced by Paris during the Twenties : the Paris which was the artistic center of the Western World - the social Paris to which Russian <WSD>aristocracy</WSD> migrated - the chic Paris which attracted the tourist dollars of rich America - the avant-garde Paris of Diaghileff , Stravinsky , Koussevitzky , Cocteau , Picasso - the laissez-faire Paris of Dadaism and ultramodern art - the Paris sympathique which took young composers to her bosom with such quick and easy enthusiasms . 
Meaning of the word marked with <WSD> tags:  a privileged class holding hereditary titles