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 Metallica co-founder wrote the power ballad "Mama Said"?" whose answer is James Hetfield.
Each document should contain about 30 words, and these documents should contain useful information.

Query: who wrote metallica song mama said
Useful Output:

Doc 1: James Hetfield wasn't afraid of getting personal in his lyrics anymore, and “Mama Said” is about his late mother. It's audible that he is
Doc 2: Mighty Metallica pushes pause on the metal long enough for James Hetfield to deliver a heavy country-rock ballad written about his mother, who
Doc 3: Buy Music. All Items · Items I Want · Purchases · Cart · Record Stores. Sell  Written-By. Kirk Hammett. Hammett*. Written-By. Lars Ulrich.
Doc 4: Though the songs are quite different, the title itself is reminiscent of Merle Haggard's most-famous song, "Mama Tried." (Interestingly, the
Doc 5: But that's just what this song is about. James Hetfield writes a letter to his Mom who passed away when he was just a teenager. It feels like he