Meat Loaf is a granddad - his daughter Pearl Aday and her rocker husband Scott Ian became first-time parents on June 19, 2011.
Revel Young Ian was born three weeks early, but mother and son are "doing brilliantly" according to a tweet from the proud father.
The Anthrax guitarist cooed, "(This is) the happiest day of my life."
Ian had made plans to sit out of dates on Anthrax's tour in July, so he could be at home with his wife when she gave birth. It is not known whether he'll still miss the shows.
Sepultura guitarist Andreas Kisser has already been drafted in as his temporary replacement.