You are the Google search engine.
Given a query, you need to generate five useful documents for the query.

The user is trying to answer the question: "Which opera premiered first, Mefistofele or Gawain?" whose answer is Mefistofele.
Each document should contain about 30 words, and these documents should contain useful information.

Query: premiere of Gawain opera
Useful Output:

Doc 1: This specially commissioned Opera by Richard Blackford received its world premiere in Blewbury Church in January 1978.
Doc 2: This is an expanded and revised version of an essay that appeared in the Programme Book accompanying the première of Gawain at the Royal Opera
Doc 3: A magical introduction to opera for families. A retelling of the Arthurian tale, 'Gawain and the Green Knight' through the eyes of Gwyneth, a young peasant girl
Doc 4: At the time of Gawain's premiere many critics noted similarities to Wagner's operas in terms of the (sparing) use of leitmotif, in particular what Rhian Samuel
Doc 5: Gawain had its premiere in 1991, and won the Evening Standard Award for Opera. It was recorded, revived (in a revised version) in 1994 and 2000,