Movement Invites Movement have a rather good point in their post Challenging the 8-Week Myth. Their point is that it takes more than 8 weeks to physically adapt to tango so the idea that you can learn tango in that time span is incorrect.
As I have been guilty of promulgating this myth I feel I should clarify one or two points.
For the past two years my introductory tango class has been a repeating 8 week cycle. The idea is that the student works through the cycle a couple of times until they are comfortable and confident. On the first pass things are new to them, on the second familiar and by the third they should be getting to grips with tango. It should also be mentioned that there are things that get covered in every class, underlining their importance. The cycle is in no way an exhaustive examination of tango but it does cover enough to establish a good foundation and allow dancers to get around a floor.
To put it simply it’s not that I think someone can learn tango in 8 classes but that there are 8 lessons to be learned. How many times the student needs to receive the lesson before they learn it is up to them.
…and now to digress.
The argument is about needing 8 classes. “The 8-week myth” implies taking one class a week. A student will not learn to tango in 8 weeks at one class a week. Why, because the distance between classes is too much. Muscle memory will not build quick enough. If the student takes two classes a week then they will learn quicker. Muscle memory will develop faster. Do not jump to the conclusion that taking two classes a week will allow you to learn tango in half the time or that taking four classes a week will get you there in a quarter of the time. Humans are not linear systems and the law of diminishing return kicks in rather quickly. At two classes a week the body will not have forgotten the lessons it learned in the previous class and at the same time the brain will have had enough time to absorb their implication.
Of course this is all academic as I am now changing to a one class method.

Firstly, we have to say, “Oops!”. Our comments were supposed to be open. Now they are
Secondly, we really like the points you’ve made here. Muscle memory plays such an important role. The general population won’t remember the corrections to the body from week to week… and so it generally takes those minimum 8 weeks just to finally muscularly digest the corrections.
As well, the idea that there are 8 lessons to learn is key. We’re not sure if it’s 6, 8, 10, etc. lessons, but we get the point.
Thank you for some more food for thought.
J&K
The Preparatory cycle went to 8 lessons because I would have been driven crazy going round and round in a cycle of 6. It really depends on what one considers fundamental tango.