Double Exposure "Ten Per Cent" (Salsoul 1976)
Disco group Double Exposure make their way into the list by virtue of releasing the first ever commercially available 12-inch single. The extra five inches' width allowed the grooves to sound fatter, louder and cleaner over a big disco sound system, as well as providing the space to deconstruct the song and rebuild it as a dance floor epic. Under remix pioneer Walter Gibbons, the sub-Temptations disco song is taken apart at the seams, then stitched back into a 10 minute-plus series of extended percussion breaks and euphoric, rushing choruses. Dance music had found its home and it was round, black and a foot wide.
and Donna Summer's "I Feel Love"
The synthesised pulse of I Feel Love lives on in its direct descendants house, trance and techno. At the height of the disco era, I Feel Love saw Donna Summer, songwriter Pete Bellote and producer Giorgio Moroder create a trance-inducing mantra that had more in common with the avant garde classical music of producers such as Steve Reich than the Bee Gees. A metronomic beat, repetitive bassline, and inane lyrics repeated over and over until they take on a transcendentally profound non-meaning, this could fit in well on any Underworld album. The order to trance had been given.
http://akuaku.org/~dav/misc/50dance.html :)