Mark Spyropoulos is the first British full-time member of the Sistine Chapel Choir; otherwise known as the Pope's choir, and one of the oldest religious choirs in the world. He rehearses for three hours every day and performs each week in St Peter's Basilica in front of thousands during papal masses, as well as for special ceremonies and events.

Last month, the choir released 'Cantate Domino' – the first ever studio recording from the Sistine Chapel. Featuring 16 tracks, including two Gregorian chants, it's a unique offering from the heart of Rome.

"It's an absolutely amazing privilege to be part of something like this," Spyropoulos told Christian Today. "I only joined the choir in March, and I'd been there for three weeks when I was put into this project, which – as you can imagine – was very surreal, but wonderfully so."

The Sistine Chapel is one of Rome's most popular attractions, and welcomes thousands of visitors from all over the world every day. But for several weeks, when it closed to tourists at 6pm, German classical record label Deutsche Grammophon would set up a studio in the chapel, and the choir would then record from about 8pm to midnight. "So it would be the middle of the night, and we'd be recording this incredible music under Michael Angelo's fresco. It was an amazing experience," Spyropoulos says.

"The music was written for that building, and of course it can be used in other places and that's fantastic, but Palestrina had that building in mind, and the music was written when the fresco was virtually still wet. So when we sing this music in that space and with that fine acoustic, there's really something quite incredible about that combination."

One of the most exciting pieces on the album is the world-premiere recording of the original version of Allegri's Miserere. Director Massimo Palombella, who was appointed to the role five years ago by Pope Benedict, went into the Vatican archives and found the original edition (Sistine Codex of 1661) and made his own transcription. "In revisiting that, he really managed to find what the music is doing and what it's about," Spyropoulos said of Palombella's achievements – he calls him "the Indiana Jones of Renaissance".

"He found insightful ways of performing the music, and so it really starts to come alive."

Though he first began his trial for the choir at the end of last year, Spyropoulos has met Pope Francis just once. Though the meeting was brief, he says the glowing reports of the pontiff's kindness and generosity of spirit are absolutely true.

"I've never met a pope before, so I didn't know the protocol. I was first in line and I wondered if I was meant to kiss his feet or something!" Spyropoulos recalls. But upon being introduced to Francis, he says he received a warm and friendly welcome.

"He said, 'You're from London!'. I replied, 'Yes, Holy Father, I am.' 'And you're singing with us!', 'That's right, Holy Father, it's a great honour'. He said, 'Wonderful! Welcome to the Vatican!'

"He was really warm and exuberant and welcoming. It was just fantastic. He really did match up with what people say. It would have been entirely acceptable for him to just give me a papal blessing, but he went out of his way to be warm and friendly and welcoming."

The pope gave special permission for Cantate Domino to be recorded, and was given the very first copy of the CD upon its release. But has he given any feedback yet? Spyropoulos laughs. "Well, I haven't heard any complaints."