I think it is easiest to tell the difference when working on stab notes. I set up for what I think is the correct shape then raise the tongue arch to the top of the mouth. Then I use the abdominal muscles to pressurize the tank. That is the Air Support. If all goes well I just release the tongue and out comes the correct note at the correct…[Read more]

I had the same confusion initially. There are only two bars that are double-tongued. All else is single-tongued or slurred. See this discussion:

https://mysterytomastery.com/topic/moderato-ab-exercises/