Romanticism in cultural history is a word that defies precise definition. In music it is most commonly applied to a period or the predominant features of that period, from the early 19th century until the early 20th. Features of romanticism in music include an attention to feeling rather than to formal symmetry, expressed in a freer use of traditional forms, an expansion of the instrumental resources of music and an extension of harmonic language. Music also reflected other preoccupations, influenced particularly by the arts of literature and painting, and their preoccupation with the remote and exotic, whether historical or geographical, or both. Early German romantic opera, for example, is found in Weber's Der Freischtz, with its plot involving woodmen and huntsmen and the mysterious midnight magic of the forest.