â??I donâ??t know where Iâ??m going from here, but I promise it wonâ??t be boring,â? David Bowie told an audience at Madison Square Garden on his 50th birthday. Itâ??s probably the quote that will be used most today to pay tribute to the singer/songwriter, who died of liver cancer yesterday at 69, and itâ??s a fitting tribute to the man whose music kept everyoneâ??even himselfâ??guessing about what was next.