Phil Lynott's storytelling lyrics are mainly what Thin Lizzy are primarily known for. But another major stylistic component was their twin guitar harmonies heard in such tunes as "Emerald." The song features both guitar harmonies and an extended guitar solo trade-off between Scott Gorham and Brian Robertson. Lynott explained that the lyrics did not refer to a specific time of Irish history, however. "No, I was just thinking of a generalization. That's why I said, 'Down from the glen came the marchin' men with their shields and their swords.' It was just to show that violence has been going on for years. You could almost relate it any period of time."