Every four or five years almost since it was launched in Tucson in 1971, Arizona Opera has performed Puccini’s popular Italian melodrama “Tosca,” and Joseph Specter has an idea why: There’s just something about Puccini that is irresistible. “Puccini and this work are always such a powerful combination of engaging people in opera,” said the Arizona Opera general director, who confessed the piece, which opens at Tucson Music Hall Saturday, Nov. 11, is one of his personal favorites.