Remember EPs?

They were phonograph records. IIRC, they were like LPs in that they were 33.3rpm with the small spindle hole, but they were smaller than an LP. They were a little bigger than a 45 rpm single and usually had 2 songs per side. I used to find them in the import section of the basement at Strawberries records in the 1980s.

:hi:

Back at ya.......:hi:

...(which stands for "extended play"), one was the kind you cite, and the size you're referring to was 10 inches. One of my favorite examples of that is my 10" Oingo Boingo debut ep "Oingo Boingo," IRS label - http://en.wikipedia.org/wiki/Oingo_Boingo_%28EP%29.

There was also the 7 inch ep, same size as a 45 (rpm), but mastered for playback at 33-1/3 rpm. Usually the 7" 33-1/3 ep would have a small spindle hole instead of the big one, as in the usual 45 rpm single.

The thing to keep in mind, the faster the speed/rpm, the higher the fidelity. So, with 7" EPs mastered at 33-1/3, "cramming" more material into a limited physical piece of vinyl, meant that the grooves cut into the master disc were cut closer together, leaving less room for recording the range of frequencies. As a result, while a 7" EP at 33-1/3 rpm could hold 3, 4, or maybe even 6 songs (depending on length), the fidelity is somewhat less.

The solution to that was to simply crank it up on playback!

I know this because I released a 7" ep with six songs on it back in 1982.