Who sang Where Have You Been ?
( The traditional histories " Old History of the Five Dynasties " and " New History of the Five Dynasties " attributed Zhang 's actions to a request by Shi to Zhang , as Shi was apprehensive that if Emperor Taizong got to meet Sang , Sang would reveal the details behind Shi 's turning against Liao , but Sima Guang , the lead author of the " Zizhi Tongjian " , found the account lacking in credibility as Zhang was acting arrogantly toward the Shi imperial household at the time such that he found it implausible that Zhang would follow any orders from Shi by that point , let alone killing Sang , and therefore concluded that Zhang killed Sang out of personal grudge . )