NEW YORK — Sony Music has promoted Thomas C. Tyrrell to exec vice president of external affairs for the major label group and tapped entertainment law vet Lisa Weiss to fill Tyrrell’s vacated posts as senior VP, general counsel and secretary.Tyrrell will be dealing with governments as well as trade groups. Weiss will handle overall legal policy. Tyrrell was senior VP for three years, prior to which he was exec VP of administration at Sony Music Intl. from 1991 to ’98. Weiss previously was senior VP and deputy general counsel and before that, a New York law firm partner.