"The singing starts again … building and building, and he rains down blows on me … and I groan and writhe … Lost in him, lost in the astral, seraphic voices … I am completely at the mercy of his expert touch …

"'What was that music?' I mumble almost inarticulately.

"'It's called Spem in Alium, a 40-part motet by Thomas Tallis.'

"'It was … overwhelming.'"

It may not quite be what Thomas Tallis, the 16th-century court composer, had in mind when he composed his extraordinary devotional choral work, Spem in Alium. After all, it is a sacred motet expressing man's hope and trust in the Lord.

But thanks to its role in this year's publishing sensation Fifty Shades of Grey, EL James's novel exploring the joys of sado-masochism, Tallis has reached the top of the UK classical music charts. The Tallis Scholars' 1985 recording of Spem in Alium has outsold even the tenor Luciano Pavarotti to reach the number one slot.

It turns out that Christian Grey, Fifty Shades of Grey's super-handsome billionaire and S&M enthusiast, enjoys practising his hobby to it. And Anastasia, the heroine of the book, whom Grey trains as his submissive partner, shares the enthusiasm.

Now, it seems, the public is flocking to do the same – or at least to enjoy the polyphonic richness of one of English music's most extraordinary compositions, in which 40 individual vocal lines are woven closely together to create a surging tapestry of sound.

Steve Smith, the producer of the Tallis Scholars' recordings, said: "I'm sure Tallis couldn't have anticipated this, but having said that there's a sort of rapture in the music, so I can understand why EL James would find it suitable for the purpose. It is very intense, and has huge climaxes in it."

Spem in Alium was composed in about 1570, during the reign of Elizabeth I. A version of it was performed at the investiture in 1610 of Prince Henry, elder brother of Charles I, who predeceased his father James I.

Smith said: "Irrespective of how it got there, it's brilliant for us to know more people are listening to the music."