While the English Wikipedia talks a bit about progressive trance, the German and Spanish ones are much more complete.
But they all miss information about the origin of progressive trance.
Even partial information is welcome, but I need at least a date and reference.
The first trance track was Age of Love - Age of Love (Jam & Spoon Mix) which came out in 1992. I have several recordings of Steve Mason's BFBS radio show from 1993-1994 where Steve announces to the audience the track he is playing is progressive trance. So the emergence of progressive trance came very quickly. As yazze has mentioned, this comes from Leftfield but the idea of instantly labeling a track "progressive" in rave music comes from House. As of June 1992, the emergence of progressive house was being reported by MixMag.
"Progressive" is a retrospective term that emerged in the 60s to qualify Jazz and Group songs which although they were stylistically complex, were aimed at being more "accessible" in their construction, falling in between what one would consider "mass audience" popular songs and more obscure or complex song, thus echoing the concept of "progressism".
It then became a popular naming convention in the 60s with the emergence Progressive Pop and Progressive Rock, which used complex instrumentalisation and composition while being constructed following popular songs format.
In the late 80s, progressive electronics emerged by integrating Minimalism and New Age music in Pop, Modern Jazz, Contemporary RnB (late 80s to early 90s RnB), Post-Rock and then went on to integrate Pop-House, Acid House and finally Trance.
In other terms, Progressive Trance emerged in the early 90s as part of a stylistic electronic movement often called "Leftfield", in reference to a popular british group which like many other 80s pop artists introduced New Age leads or patches, on House and Trance oriented tracks.
