For the release of "Blue Blood Blues," the new single by his band The Dead Weather, the rock demi-god has invented the Triple Decker Record – a 7-inch disc that comes inside a 12-inch record.

These are all still 78 rpm. But a funny thing happened in 1949 -- the 7-inch disc re-emerged. RCA began secretly working on a smaller format in the early 1940s, according to Biel. He says the ...

It was originally sold in conjunction with a special record player that required a wide record spindle that fit the larger hole in the smaller 7-inch disc. Eventually the dueling formats wound up ...