An aria is a song for a solo voice with orchestral accompaniment. It is typically found in an opera or oratorio, but also cantatas and even in musical theatre.
You can hear an aria in an opera house or concert hall. Many cities have opera houses that offer performances of operas throughout the year. You can also listen to arias online on websites such as YouTube.
Here's an example of an aria: "Nessun Dorma" from the opera Turandot by Giacomo Puccini.
