a single, derived from back in the day of 12 inch vinyls which typically had one song.
also 1,2 because single songs on a 12 inch vinly were easier to switch and mix on a 2-deck turnatable
nowadays it is considered normally as the first single to be released from an upcoming album and referred to as a promo track
"One two, one two, one two, one two
So you wanna start up, what we gonna tear shit up?
I said let the turntables talk for me at first
And then I should finish the rest"
-X-ecutioners "Live form the pj's"
The best mix that a song can have. It is usually longer, easier to mix, and you can juggle beats from the instrumental with the main 12" mix on a pair of decks.
12" is the way to gop for good mixes and to get good crowd reactions.
It's 12 Districts in the greater city of Atlanta. There are always 12 officers on patrol at all times in each district and each officer works 12 hour shifts! That why ATL says "12" when referring to police.