Final answer:
Darrow performs the a. waltz for Matteo during training, which is a dance typically done in closed position and triple time.
Step-by-step explanation:
The dance that Darrow performs for Matteo during training is the a. waltz. The waltz is a smooth, progressive ballroom and folk dance, usually in triple time, performed primarily in closed position.
This scene captures a moment of character development and relationship building between the characters in a setting that juxtaposes the elegance of dance with the harsh realities they are often dealing with.