11 Operas in 10 Minutes

Operas don't appeal to the typical high school student. Nonetheless, teachers of music theory and music appreciation classes do try to expose their students to the opera. The video below covers the story lines of eleven classic operas.

A similar, though not quite as well-produced video covers ten other operas below.

Thanks to Open Culture for the first video.

Applications for Education

Although certainly not an in-depth analysis or summary of any opera, the videos below could be useful as review or introduction resources for a music appreciation course.

On a related note, you might want to check out Shmoop's list of study materials related to Shakespeare.

Here are some related items that may be of interest to you:
Arts Edge - Podcasts and Lesson Plans
Classics for Kids - Classical Music Lesson Plans
Keeping Score - Study the Symphony