# Es war einmal

> opera by Alexander von Zemlinsky

**Wikidata**: [Q3057622](https://www.wikidata.org/wiki/Q3057622)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Es_war_einmal)  
**Source**: https://4ort.xyz/entity/es-war-einmal


## References

1. MusicBrainz
2. Freebase Data Dumps. 2013
3. Music Since 1900 (6th edition)
4. Virtual Study of Theatre Institute