Which among the following is NOT an American Slave narrative?

The correct option is Songs of Enchantment.

To understand why this is the correct answer, we can look at the origins and genres of each of the given works:
1. Songs of Enchantment: This is a 1996 novel by the famous Nigerian author Ben Okri. It is a work of modern African literature and magical realism, serving as a sequel to his Booker Prize-winning novel The Famished Road. Because it is a contemporary fictional novel written by a Nigerian author, it is not an American slave narrative.
2. The Interesting Narrative of the Life of Olaudah Equiano: Published in 1789, this is one of the most famous early slave narratives. It details Olaudah Equiano's life from his kidnapping in Africa, his time enslaved in the Americas and the Caribbean, to his purchase of his own freedom and his life as an abolitionist in England.
3. Life and Adventures of Henry Bibb: Published in 1849, this is a classic autobiographical American slave narrative written by Henry Bibb, who was born into slavery in Kentucky and later escaped to become an activist and abolitionist lecturer.
4. Narrative of Solomon Northup: Subtitled Twelve Years a Slave and published in 1853, this is a prominent memoir and slave narrative by Solomon Northup, a free-born African American from New York who was kidnapped and sold into slavery in the Deep South before regaining his freedom.

Therefore, while the other three works are renowned historical slave narratives documenting the experiences of enslaved individuals, Songs of Enchantment is a modern work of fiction and is NOT an American slave narrative.