Between oratorio and sacred opera

 Well, it's opera:

And it's oratorio:

Can you see the difference?
Great, oratorio is like opera, but without any costumes and spectacular additional "things".
So, now let me explain you something.
The difference between opera and oratorio is easy to recognise and describe in one sentence, but it's not for musicologists.
Who is a musicologst? Here you go:
http://nonsensopedia.wikia.com/wiki/Muzykolog (in Polish, I'm sorry for this, but it's so perfect)

We like complicated. Complicated is good.

Now you'll understand better this short article (20 pp.) about the difference between one of the types of opera and oratorio in a short distance of time.

Enjoy!

PS. It was a plan to write a post about history of opera, explaining everything in a way that we, musicologists, like, but it appears that not this time. Sorry again.

https://drive.google.com/file/d/0BwDJIHI_x7ddWjVNem5kNmxvQjA/view?usp=sharing

...and my source: http://www.jstor.org/stable/765929?Search=yes&resultItemClick=true&searchText=oratorio&searchText=and&searchText=sacred&searchText=opera&searchUri=%2Faction%2FdoBasicSearch%3FQuery%3Doratorio%2Band%2Bsacred%2Bopera%26amp%3Bacc%3Doff%26amp%3Bwc%3Don%26amp%3Bfc%3Doff%26amp%3Bgroup%3Dnone&seq=1#page_scan_tab_contents

...And also some words from the text:

Anachronistic – not adequate to the period of time we talk about.

Are you aware of the fact that you use an anachronistic language?

The costumes in the movie are anachronistic, they couldn't have existed that time.

Impresario – a person who is responsible for creating a programme as well as for the economical stuff in the opera theatre, esp. In the 17^th and 18^th century.

Handel didn't stage Ariodante because of teh argument with opera's impresario.

He was an impresario in San Cassiano.

Harpsichord – an instrument, similar to piano, used commonly in the 17^th and 18^th century.

I've learned playing harpsichord for 12 years.

She's well known harpsichord player.

Explicit – stated in a very clear, easy to understand way.

Her speech was definitely explicit.

The explicit claim formulated in the article made me think about it.

Prominent – outstanding and brilliant, better than others.

Your homework is prominent, you get A from me.

His prominent BA thesis is even published.