Grand jetés may look effortless, but they’re anything but: A ballerina must leap into a soaring split three feet off the ground before landing (elegantly, of course) on one leg. Typically, she gets an added boost by driving her arms into the air—unless it’s an August Bournonville ballet. The Danish choreographer’s technique distinguishes itself from better-known Russian forms with its constant movement and subdued arm motions. Such is the challenge Maria Mosina undertakes this month when Colorado Ballet opens its season with Bournonville’s La Sylphide on October 2. (A sylph is a spiritlike being.) Here, Mosina—who made her debut as a principal dancer for the company in the role of La Sylphide’s fairy 19 years ago—demonstrates what makes a Bournonville grand jeté…well, grand.

—Photograph by Allen Birnbach