Does a Bladesinger need to have her weapon in hand to Bladesong?

@ProfSiccusDoes a Bladesinger need to have his or her weapon in hand in order to utilize the Bladesong ability? No.

— Jeremy Crawford (@JeremyECrawford) April 4, 2016

Bladesong doesn't require concentration. Its description would say if it did. #DnD https://t.co/7KtatKlOrR

— Jeremy Crawford (@JeremyECrawford) April 4, 2016

@JeremyECrawford Bladesong's description doesn't seem to say that the bladesinger must be wielding a weapon to invoke it; is one required?

— X (@x93temp) April 4, 2016

Bladesong doesn't require a weapon in hand. Its description would say if it did. #DnD https://t.co/DoSnYvbEcc

— Jeremy Crawford (@JeremyECrawford) April 4, 2016