Why is The Playboy of the Western World considered a modern play ?
J.M. Synge's The Playboy of the Western World is often considered a modern play because of it's representation of the rural Irish peasantry. Rather than depicting the rural Irish population as idealized and noble figures (as was popular at the time), Synge showed them as complex and flawed. Synge's peasants are at times bigoted and violent people (they idealize a man who "killed his father," after all), although they also show a real flair for colorful, poetic language and narration. As such, Synge doesn't paint rural Irish life in idealized tones, but instead tries to show it as a complex, flawed, multifaceted experience.
Though the play might seem tame now, Synge's depiction of Ireland's rural population caused an uproar in his day. The idealization of the Irish peasantry was an important component of the Irish nationalist movement, as Irish writers and patriots tried to use a heroic past and virtuous traditions to prove that the Irish had no need of English rule. While this tendency was noble in theory (it was, after all, part of an attempt to win freedom after long years of English rule), it also tended to blindly idealize the Irish peasantry in unrealistic ways. Synge's refusal to do so was highly rebellious, and indeed could be seen as a dangerously subversive attack on nationalist ideals. All in all, the urge to deconstruct the foundations of traditions is often a hallmark of modern literature, and so Synge's deconstruction of the idealized Irish peasantry is one of the main reasons Playboy is considered a modern play.