'Communicative' describes the overall purpose of learning and teaching a modern language.Is it really the case that people trying to organise language teaching, in previous decades / centuries / millenia, have never previously focused on helping others to communicate?Food analogies are not altogether helpful in linguistics.
I'm guessing a young Keith Emerson probably played this album a lot when Emerson Lake & Palmer were writing Brain Salad Surgery.
The Fight predates prog by a good ten years and is almost certainly the template for ELP's Karn Evil 9; God knows what the jazzers made of this when it landed on their turntables.
All learners of languages build up their skills partly by recognising and using structural patterns. Hard as I tried to absorb these ideas on my MA Course in 1984, they were never as much use in my teaching as less theoretical works such as Streamline Departures structured to provide learners with entry-points into an unfamiliar language system.
I know of no language course books for low level learners which do not have a structural thread, no matter how they are otherwise described by authors and publishers. At pre-intermediate level, I got on fine with Brian Abbs' and Ingrid Freebairn's Building Strategies, which they billed as a Notional / Functional approach. The Council of Europe's Waystage  and Threshold  syllabus specifications - at the pre-intermediate and intermediate levels respectively - also managed to specify a functional syllabus without abandoning reference to structural patterns.
My learners were disorientated by absence of a clear structural thread and did not feel that they were making any progress in their studies.
These last two coursebooks enjoyed a disappointingly short shelf-life in the school where I taught.Yet, the adjective 'synthetic' is also used in the dictionary to mean 'unnatural'.Characterising the structural syllabus as 'unnatural' in order to validate something called 'The Natural Approach' as having more to do with communication, was not Wilkins' intention.These were much based on the L2 everyday spoken English needs of the non-breadwinners in the refugee families e.g.doing the shopping, getting up in the morning, going to school.Find materials for this course in the pages linked along the left. Use OCW to guide your own life-long learning, or to teach others.