50 State Quarters to form what is known as a "mule". Only sixteen of these specimens, produced on dollar planchets, escaped from the mint. A 2005 Minnesota double die quarter, as well as a 2005 Minnesota quarter with extra trees (another die error), have both triggered numismatic interest. An unusual die break on some 2005 Kansas quarters created a humpback bison. Relatively more common are Kansas quarters bearing the motto "IN GOD WE RUST." The United States produces proof coinage in circulating base metal and, since 1992, in separately sold sets with the dimes, quarters, and half-dollars in silver. For the silver issues,
What Time Is Love? for sampling", and suggested "We might put out a couple of 12-inch records under the name The K.L.F., these will be rap free just pure dance music, so don't expect to see them reviewed in the music papers." The first incarnation of "What Time Is Love?" followed. "What Time Is Love?" became one of The KLF's central tracks, dubbed their "three-note warhorse of a signature tune" by Bill Drummond, in reference to the three-note bassline which, together with a high-pitched refrain on two notes (B bending to F#) characterises the song. The bassline is very similar to the one used