Quintessential Vocal Ensemble was created in 1993.

"Alice's elegant manners and sophisticated taste make her the quintessential example of a refined lady."

The classic novel is often regarded as a quintessential example of American literature.

"Quintessential" is an adjective that describes the perfect example of a particular type, The quintessential quarterback would be one who has all of the traits and qualities those who are knowledgeable about football would expect from a quarterback. There are quintessential villains and heroes. It could be that "quintessential" is generally used to describe people, but that may not be necessarily true.

No, "quintessential" is not a noun. It is an adjective used to describe something as representing the most perfect or typical example of a quality or class.