While her mother is away on business, a young girl home alone with her older brother witnesses her neighbor's kidnapping. But no one believes her--not her brother, not the cops. So she takes matters into her own hands putting her life at risk to save her neighbor.

音乐剧《曾经》叙述了卖花女被街头艺人的音乐所吸引，两人都有着对音乐的热爱和痴迷。在一次合奏中，他们找到了彼此间惊人的默契。这个发现让他们兴奋，很快他们找到了另外的一个同伴，组成了一个乐队，并通过优秀的表现得到了专业人士的肯定。与此同时，爱情也在逐渐萌芽。音乐是这部剧作最大的亮点之一，塑造了极其浪漫唯美的氛围。