They do normally' date=' but In Rainbows ran at 45 RPM. I believe it provides a higher fidelity, like a higher bit-rate for mp3's. [/quote'] Radiohead has been doing that for a while, look through Radiohead in a record store and you'll find lots of neat stuff, like Kid A on 2 10in 45's, rather than a single 33 1/3. They also have a bunch of 12" 45rpm singles which sound amazing. I've got one, it has "Pyramid Song" on one side, "Fast Track" and "The Amazing Sound of Orgy" on the b side. Mind blowing hi-fi. I don't understand it all but my best description is the grooves can be cut deeper with a 45, allowing for higher peaks. More information passes to the stylus in a shorter amount of time. So it is like an analog version of a higher bit rate.