"A seven-stringed harp", as referenced by Will Cuppy in the first chapter about the Pharaoh Cheops or Khufu, in his book "The Decline and Fall of Practically Everybody." Dorset Press, New York, 1950. Cuppy was most certainly kidding, since the book was a satire, but I felt it was important to know that the fabrication of the term preceded "The Big Bang Theory" by about 60 years.
from the text:
"Personally, I would call the royal harem one of Khufu's main interests in life and one of his claims to our attention. Although we lack statistics, it must have been one of the largest in the ancient world, completely equipped with the very best concubines obtainable in Africa, all skilled in dancing, singing and playing on the bazinga, or seven-stringed harp."