1981. For that mix, I introduced a little bit more Hip Hop; with the Sugarhill Gang you can't go wrong - especially with the 8th wonder (long version). I mixed the Ambient/modern classical part in the middle.
I find sometimes hard to move from one genre to the other and it's been a difficulty throughout this long project. I generally mix each section individually so that I can keep the move and the atmosphere. Then I edit each parts. For instance, I'll mix the funk/soul/R&B section, then I'll mix the ambient section, then I'll mix the disco section. When all parts are done, I edit them to make a whole mix. That way the mix, as a whole, remains cohesive.