I used to be confused, but now i'm constantly irritated by the 'counting in beats' concept in the tachnique books.
Example (From the Guy Howard Technique of Ballroom dancing 2011 edition) "Time signature 2/4. 33 to 34 bars per minute. Counting in beats and bars: 1 and 2 and, 2 and 2 and, 3 and 2 and, etc"
Now, there is something very confusing here. 2/4 is 2 beats per bar. 33 bars per minute therefore means 66 beats per minute. But of course, listen to any tango dance music and it's very obviously about double this (i.e. 132 beats per minute. (slightly slower these days but i'm using Howards numbers.)
Counting it '1 and 2 and' is a complete fudge. There is the accenting of the beats of course, but it simply translates as beats 1 and 3 being equally accented.
In slow waltz, foxtrot, quickstep, an 'AND' is a half beat. Tango music can be in 4/4 time anyway (i have tango sheet music which is written with this time signature). We wouldn't say foxtrot music is written 1 and 2 and with the second beat slightly less accented. How confusing that would be.
OK rant over

I've just noticed that in the 'learning centre' here, the tango time signature is given as 4/4. Well done Jonathan. Some sense at last!

Geoffrey Hearn (A Technique of Advanced Standard Ballroom Figures) repeats the 'standard' convention of counting tango as a slow two, not a fast four, but then his charts are written in four, with the bizarre result that 'Quarter Beats' is given as having four 1/2 beats!

It is a fudge. I feel the music as being in a fast two STRONG, weak, STRONG, weak, so so march time, but at the faster tempo, not the slower one.

Herein lies the problem.. tango was ( back in the 40s ) primarily a 2/4 sign. as was QS.. both changed early 50s to 4/4 , adapting to the newer styles being written .

It really changed the way " danced " both from a musical standpoint .

Teaching sites I have watched on you-_tube .None of them count the Tango in 2/4 time. Why don't the Technique Books up-date. Or rather why did n't they
up-date

It would be just as valid to ask the teachers why they present this important aspect of technique at variance with the standard technique of every significant teaching society in the world.

I too have always been very irritated by the technique books use of 2/4 for tango and the simple mathematics process leading to an incorrect tempo.
I found it made the exam more difficult having to remember how many times I had said "2" while concentrating on demonstrating a figure and counting "1 and 2 and 2 and 2 and ..."

Guests statement about "this important aspect of technique" has now led me to dig around a bit more and I offer the following for consideration:

I'm not convinced that counting in beats and bars is an important aspect of technique for a typical dancer. It makes no difference to them how many bars a particular figure occupies, they just need to be able to dance it to the music. Slows and Quicks make more sense and are much more useful.
A teacher/coach/choreographer may need to count beats and bars when creating a fixed length routine or trying to match phrasing but not otherwise.

I believe the root of the confusion lies in a fundamental difference in the way a dancer and a musician use beats and bars.
A musician starts by setting the tempo in beats per minute, then builds bars from there for ease of reading and referencing the music.
A dancer hears the music tempo in bars per minute, then breaks the bars down to fit in the steps.
I believe the early dancers heard the tango as 30-32 bars per minute. They were then told it was written in 2/4 time so allocated two slow beats to the bar.

I finish with some quotes from Henry Jacques "Modern Ballroom Dancing", 1944, which I believe demonstrates this early thinking and may explain the origin of the 1&2& count.

"A technical knowledge of music is by no means essential to the aspirant dancer. Indeed, many highly skilled amateurs do not know the first thing about it"

"In Tango there are usually two beats, although Tango music is very occasionally written with four beats to the bar"

"When counting in 4/4 time we usually reckon in "Slows" and "Quicks", each "Slow" representing two beats and each "Quick" one beat. Thus "Slow, Quick, Quick" would occupy one bar of music.

The Tango is not quite so easy for the novice to distinguish. Indeed, even to the expert a badly played Tango often sound like a Foxtrot. Even though there are only two beats to each bar, there is also a sort of echo to each beat. Thus when counting Tango Time we say: One "and" Two "and" to each bar. In my lessons on Tango, however, I shall use the simpler Slows and Quicks as well as the number of beats."

I must admit to following the guidance of that final sentance!

It is not contrary to standard technique to count tango in slows & quicks. The real difference is not that a 'slow' count is represented by one beat, whereas in foxtrot or quickstep it would be two. But tango is traditionally reckoned to be in March time, which doesn't have the same stress pattern as common time. March time has a stress on beat 1, whereas common time has a primary stress on 1 and a secondary stress on 3. They're not the same, or interchangeable, however much individual dancers wish to blur the distinction.