There's a publicity photograph of bandleader Kay Kyser which is currently on sale on the auction site ebay. The auction page includes an image of the reverse side of the photograph, on which a date is stamped: December 1, 1949. This is the day that Kay Kyser's weekly television program (a program profiled at length in my book about early TV) made its debut on NBC Television.
http://cgi.ebay.com/1949-Orchestra-Leader-Kay-Kyser-Press-Photo-/260818400338?pt=Art_Photo_Images&hash=item3cb9fcf452