Guitarist Henry Mccullough, who performed with bands including Wings, is seriously ill after suffering a heart attack on Monday (05Nov12).
Despite reports suggesting the Northern Irish musician had passed away, his sister Rae Morrison insists he is still alive, but gravely ill and under doctors' care at the Causeway Hospital in Coleraine.
She tells Britain's Bbc, "He is a very special person. We really are very worried for him, his (other) sister is on her way home from Florida and his brother is coming home from Glasgow."
MCCullough performed with Sir Paul MCCartney and Wings in the 1970s and was a member of Joe Cocker's band.
There are currently five separate teams working on 'Game of Thrones' projects at HBO.
She's a big fan of the band and this week she got to perform with them.