NEW YORK: Recording label EMI Classics said it is releasing a compilation of classical music that inspired the author of the erotic “Fifty Shades of Grey” trilogy.

In a statement, it said the 15-track album of pieces referenced in EL James' best-sellers will be available in North America digitally from August 21 and in CD format on September 18.

Outside Canada and the United States, both formats will be released on September 17.

“I am thrilled that the classical pieces that inspired me while I wrote the 'Fifty Shades' trilogy are being brought together in one collection for all lovers of the books to enjoy,” said James in the EMI statement.

EMI said the books' references to classical music have spurred sales of such otherwise little-known pieces as “Spem in Alium,” a 16th-century motet for 40 choral voices by the English composer Thomas Tallis.

Other tracks – drawn from EMI's rich back catalog – will include “Flower Duet” from Lakme, Pachelbel's “Canon” in D and the aria from Bach's “Goldberg Variations.” More than 20 million copies of the 'Fifty Shades' trilogy have been sold in the United States so far, making Americans the biggest enthusiasts of the tale of a young literature student and her sadistic, wealthy lover.