Master teacher and former trumpet with Chicago Symphony Orchestra, Vincent Cichowicz, is well known for his concept "flow studies". That this concept is closely linked to H.L. Clarke is maybe not known to all?
ITG Journal Vol. 23 No. 2 (page
BB: What prompted the concept of "flow studies"?
VC: It was Clarke's contention that long-tone studies were potential dangerous. This brought me to the concept of flow studies. He dismissed long tones as being unimportant and wrote his Technical Studies, which in my opinion are somewhat misunderstood. While it appears to be a book devoted to finger dexterity, it really should be thought of as a series of long tone studies. The ability to move through different notes (first in simple patterns and then in more complex ones), has the rhythmic energy to encourage air to move through the instrument. Long notes can have a tendency to allow the air to become stagnant. His idea was to not only improve finger dexterity but more importantly, solidify the way we make sound.
In a masterclass at the ITG Conference in 1999, Cichowicz had all the participants work on the Technical Studies. Here is a quote from the masteclass:
"The second warm-up Cichowicz asked Birnschein to do was the Clarke Second Study (a favorite one for his students). This is where the aspect of inhalation was addressed in depth. The "sticky" start of Birnschein's playing was a result of his initial inhalation. At this point, Cichowicz had Birnschein do air/wind patterns on the exercise. After several attempts, Birnschein produced the desired effect."