Extended Versions of Goldies from 80´s & 90´s by Dj Licas

a little bit of History, from https://blog.discogs.com/:

Coming to prominence in that mid-1970s disco era — 12-inch records were initially called “Disco Disks” — these singles were usually cut at 45 RPM with wider grooves, giving the songs more volume and power while allowing space on the B-side for extended cuts, remixes, and instrumentals. Producers enjoyed the freedom of stretching songs well past the previous 7-inch time constraints. DJs, the primary audience for the 12-inch, immediately loved the lengthier cuts filled with booming bass as they were ripe for a bangin’ time at the discotheque.

Interestingly, 12-inch singles were originally a fortuitous mistake. Tom Moulton, who was neither a DJ nor a musician at the time but is now known as “the father of the disco mix,” simply had the ear for a hit record and an immense passion for music. After making his name known by creating elongated mixes of funk, soul, and early disco hits, Moulton and mastering engineer José Rodriguez created the 12-inch out of necessity: they had to finish a mix by the end of the weekend and were out of 7-inch blanks. Moulton stretched out the grooves to fill in the 12-inch blank, and history was written.

While there are some conflicting reports on the very first 12-inch single, Moulton points to I’ll Be Holding On by Al Downing.