Many choreographers present and past have crossed the line between modern dance and classical ballet in the modes of expression and creation, so this is not an easy question to answer.
Generally speaking in history, for classical ballet women wear pointe shoes and the men perform in soft ballet slippers. The style of dance has connections with the courts in Italy and France in the 16th and 17th centuries and generally had a very aristocratic bearing and courtly gestures. There was a manner of graciousness and when the pointe shoes made its appearance later on, the quality of lightness was also sought after. The long tutus became shortened as romantic ballets developed into classical works.
By the early 20th century there were individuals who wanted to liberate themselves from the stricter formats of ballet – the corseted costumes and the aristocratic connotations. So corsets were removed and the feet were free of shoes. A type of more liberated dancing was experimented with and even ballet created revolutions in theatres by its connection with earthier movements, the lack of overly turned-out legs and feet and more dramatic themes. This is when modern dance was born. As a reaction on the ballet technique, modern dance was looking for more freedom within the techniques and /or more use of gravity. Modern Dance uses the floor for example where ballet dancers stay on their feet.
This diversity became the predecessor for different modalities of modern dance. After WWll, the division became even more delineated with modern dance companies and schools forming – especially in the US, England and Germany. Even classical ballet borrowed themes from folk dances and contemporary styles, so a question of “what is pure ballet?” would also receive many different answers.
If generalisations were allowed, one can say that if a dance piece contains pointe shoes and tutus for women and soft ballet shoes for men in tights, overly turned-out legs, strictly pointed feet, mostly upright bodies and set choreographed movements to classically based music, then one would probably consider it as Ballet. If dancers are barefoot, have more grounded movements (including those where the body is horizontal to or on the floor), pointed or flexed feet, freedom of movement and use of the entire body, possible moments of improvisation and the upper body is more involved in the initiation of movement, then it is most likely a modern dance piece.
Having said this, there are many exceptions to the rule. Many choreographers dance between the cracks. They might use a ballet base with modern/contemporary dynamics, or use a classical ballet form, but exaggerate it to create a post classical style, or use classically trained dancers in a work that uses both modern and classical techniques, or combine modern dancers with ballet dancers in the same work. At Love of Dance Academy we like to experiment with different styles of dance and we do not mind when one style is used in combination with another.
Choreographers are becoming more and more experimental and dancers need techniques that prepare them for any kind of work. At Love of Dance Academy, we strive to equip our students with the skills that they need to be versatile dancers.