Who wrote the book of the seven seals?

who's that writin?

John the Revelator

I think it's John of Patmos

I think it was John of Grisham.. Or King Stephen.

Possibly Thomas Clancyus.

St. John the Divine wrote the Book of Revelations
Following is the New American Standard Version of the Bible

5:1
I saw in the right hand of Him who sat on the throne a book written inside and on the back, sealed up with seven seals.
5:2
And I saw a strong angel proclaiming with a loud voice, "Who is worthy to open the book and to break its seals ?"
5:3
And no one in heaven or on the earth or under the earth was able to open the book or to look into it.
5:4
Then I began to weep greatly because no one was found worthy to open the book or to look into it;
5:5
and one of the elders *said to me, "Stop weeping; behold, the Lion that is from the tribe of Judah, the Root of David , has overcome so as to open the book and its seven seals."

Since the topic you wrote about was Blues, I gotta guess you're referring to the song, "John The Revelator", by Eddie "Son" House......the song goes:
"Who's that talkin', John the Revelator, wrote the book of the seven seals".
Son was hugely influential in pre-WWll blues. Hope this helps sort things out for ya.

The apostle John on the Isle of Patmos. Its referred to in the book of Revelations in the Bible. As previously mentioned, its also referred to in the John The Revelator song.

Book of the Seven Seals is a surprisingly cheerful account of the Apocalypse sung by The Pattersonaires, it is the title track their 1984 release.
This is old-school gospel singing, take a listen to their complexly harmonized, triple-meter arrangement of "How Great Thou Art" found on the same CD.

Blind Willie Johnson predated Son House (I think). Great tune. A master of slide guitar. I thought he sings "Who's that ridin'?" It sounds like his wife answers "John The Revelator!" I love the part where he says "he redeems us and restores us with the blood..."