Opera singer Bryn Terfel has recorded a "duet" with the late Bing Crosby in a version of his classic White Christmas.
Producers combined Terfel's voice and that of Crosby, who died 33 years ago, in a concert hall at the Wales Millennium Centre in Cardiff.
Both artists have the same record label, which has the rights to the release.
Bryn Terfel said: "It's a beautiful song".
The star revealed it took two sessions to record the song because of the difficulty involved in blending his vocals and new orchestration in with the original.
He said: "In the studio they play the original track, then me, the orchestra and the choir try and sing it at exactly same time.
"It wasn't very easy. That's why it needed two sessions which is unheard of."
He also talked about the strangeness of recording the festive classic at the height of summer.
He said: "We recorded this in July. We had people coming into the studio in Christmas hats.
"But you know, hearing White Christmas, it's still as good as it was.
"We always had music in the background during Christmas and White Christmas was always there."
The single will appear on an album of carols and Christmas songs from around the world and Wales, to be released in December.
Producer Sid McLauchlan said: "We didn't know it was going to work until we were in the studio."
He said they had to work out the instrumentation used in the original recording and write it out for their 60-piece orchestra.
"We recorded a new orchestra but at the same time it's mixed with the old orchestra.
"It has the added advantage that it's got more vintage. It gives the whole thing a different quality. You don't think it sounds old but you know it's not new either."
Mr McLauchlan said bass-baritone Terfel faced a similar challenge when delivering his part.
He said: "Bing is very flexible in where he puts his voice. That was a real challenge for Bryn. He had to try to find those same spots, singing everything in harmony.
"It's hard enough to sing when someone is with you but when the person is only virtually there, when you have only the voice, it's much more so.
"He had to really rely on his own ears and feelings for the right way for him and Bing to sync up to make it match."
Terfel will be hoping for more success with the single than he enjoyed the last time he released a version - his 2000 cover of White Christmas failed to chart.
Bookies have put the new version at 6-1 to top the charts.
Terfel said: "Odds of 6-1 - that's not bad."