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, let us look at the background of each of the works listed in the options:
1. The Interesting Narrative of the Life of Olaudah Equiano (1789) is a classic autobiography written by Olaudah Equiano, which depicts his time spent in enslavement and his attempts at becoming an independent man. It is a foundational American and British slave narrative.
2. Life and Adventures of Henry Bibb (1849) is an American slave narrative written by Henry Bibb, who was born into slavery and later became an author and activist.
3. Narrative of Solomon Northup (also known as Twelve Years a Slave, published in 1853) is a memoir and slave narrative by Solomon Northup, a free African-American man from New York who was kidnapped and sold into slavery.
4. Songs of Enchantment (1993) is a novel written by the Booker Prize-winning Nigerian novelist Ben Okri. It is a work of fiction that belongs to the genre of magical realism and African literature, rather than an American slave narrative.

Therefore, Songs of Enchantment is NOT an American slave narrative.