An organist whose musical tribute to David Bowie at Glasgow's Kelvingrove Museum went viral said he felt "overwhelmed" by the response.
Chris Nickol decided to play Life on Mars during the regular lunchtime organ recital, after hearing of the singer's death on the morning news bulletins.
Mobile phone footage of the performance has been viewed more than 1.7 million times on Facebook alone.
Mr Nickol said it was a measure of Bowie's "song writing genius".
"I heard about the David Bowie story on the eight o'clock news - and it was the lead the story," he told BBC Radio Scotland's John Beattie programme.
"It was the lead story throughout the day - a big, big event - so I thought it would be appropriate to make a musical acknowledgement of this.
"I've known Life on Mars. I'm quite ancient, in my 50s, so I can remember hearing Life on Mars when I was a pop picker in the 1970s.
"I thought that would be a good song to do, it's very melodic, got some good harmonies, it would work well on the organ - and I thought it would be appropriate to play it as it was very much topical yesterday - and a great piece of music."
Mr Nickol said he watched Bowie performing the song on YouTube to check some of the chords and harmonies before leaving for work at the Kelvingrove Art Gallery and Museum.
And he confessed to suffering a few nerves before playing one of Bowie's best known hits during the gallery's daily organ recital.
"I was quite nervous because it's a well known song and I didn't want to mess it up. It was nerve wracking but enjoyable too because it's a very, very good piece of music. It's a wonderful song," he said.
"There was quite a lot of strong applause and I was told afterwards by the Kelvingrove staff that people had reacted emotionally, which is very gratifying - a tribute to Bowie's wonderful song writing. It's a great, great song, one of many."
Artist Gordon Wilson, who filmed the tribute on his mobile phone, was in the gallery seeking inspiration after a frustrating morning in the studio when the organist started playing.
"It was one of those moments when the hairs on the back of the head just pricked up. So I just picked up my camera and I was in the right place at the right time," he said.
"It was the strangest thing. People literally started coming out of the little corridors and all the galleries. People just suddenly appeared.
"In the main concourse, people just stopped. You could still hear kids running around - but people were just in rapture.
"It was so amazing. I've never heard Bowie like that before. The man just played a blinder. I was welling up and I could see people beside me welling up - and it was just crazy."
Since posting the video on Facebook he has received private messages from across the world and 600 friend requests.
He added: "The general consensus is that the video brought a tear to people's eyes as it did for me. I'm really honoured to be part of the day.
"It was a horrible sad day that ended in a sort of joyful thing. I think it was a fitting tribute."
Organist Chris Niclol said he was surprised but delighted the clip had become a huge internet hit.
"I'm quite overwhelmed. It's very gratifying that the Kelvingrove organ, the wonderful sound of the Kelvingrove organ has been heard far and wide - and great that Bowie's fantastic song writing genius is also being heard far and wide.
"It really is a most wonderful, wonderful song."
He also described the challenges of adapting the song for the organ.
"There are some interesting harmonies that are not standard chords. They're interesting so I had to check them out. It does kind of unexpected things which is often the way with Bowie. It's a very inventive song, very creative, very imaginative."