Ed Sheeran revealed he has a guitar in every room of his house as he announced he is giving away two of the signed instruments.
The Shape Of You singer-songwriter made a rare appearance online on Friday to announce the competition, as he takes a break from music following the birth of his first child.
Sheeran is marking two years of partnership with Northern Ireland firm Lowden, his chosen brand of acoustic guitar makers.
The instruments will be given away at random via the comments on the YouTube video.
Both instruments have been used by Sheeran during recording sessions and another of the family-run company's creations appears in the video for his surprise track Afterglow, released in December.
Sheeran said: "I've actually got a Lowden guitar in every single room of the house... they're scattered around, because it's just nice to walk into a room and have a beautiful instrument there that you can pick up and play."
Speaking about the range, he added: "It was important for the 13-year-old in me being able to get the quality of a Lowden guitar but also it not be an unachievable feat.
"I personally think it's better than anything else in its price bracket."
Sheeran and founder George Lowden also announced upgrades to the Sheeran by Lowden range of guitars, including the addition of Indian rosewood on four models.
Lowden said: "For me to try to set up a new workshop to make the guitars here (in Northern Ireland) was a big challenge. But we're two years down the line now and everything is going very well.
"We've got a really good team now who have been trained from scratch, and have developed high-tech ways of making the Sheeran by Lowden. It's a whole different ball game."
Commenting on the build process, he added: "The guitars still feature hand touches, though. We still carve the internal struts with Japanese chisels, for example, so there's a kind of mix of high tech and traditional skills."
Lowden Guitars dates back to 1961 when George started making the instruments with his boat builder father using fishing line for strings.
He opened his first workshop in Bangor, Co Down, in 1977.
Lowden guitars are now sold across the world and have been played by stars including Gary Lightbody of Snow Patrol and Eric Clapton.
Sheeran announced the birth of his daughter Lyra with his wife Cherry Seaborn in September.
He wrote online: "We are completely in love with her. Both mum and baby are doing amazing and we are on cloud nine over here."
Despite being on a break from music, he surprised fans with a "Christmas present" new single, Afterglow, in December.
Two winners will be selected at random and announced via Sheeran by Lowden's Instagram and online at www.sheeranguitars.com.
More information at youtube.com/sheeranguitars.