Ben Nicholson's March 55 (Amethyst) has sold for £1m ($1.4m) at Christie's.
The lot crossed the block in an auction of Sting's personal collection of art and artefacts in London earlier today, achieving an increase of 104% on a valuation of £500,000 ($695,687).
Nicholson was a British artist who spent much of his career living and working in St Ives. He was married to Barbara Hepworth between 1938 and 1951.
He painted the piece in the mid-1950s, often considered the high watermark of Nicholson's career.
His work was displayed at the Tate Gallery in London and the Venice Biennale, and in 40 major exhibitions held by the British Council between 1947 and 1960.
Sting's Steinway grand piano made £116,500 ($162,634), beating an estimate of £50,000 ($69,568) by 133%.
The piano has stood in Sting's London home since 2002.
Christie's comments: "Sting's Steinway grand piano occupied pride of place in the music room at Queen Anne's Gate.
"Sting worked extensively with this piano for a decade, specifically on three albums: Songs from the Labyrinth, If on a Winter's Night..., and The Last Ship.
"The world renowned Steinway & Sons was established in New York, and this model B-137185 grand piano was registered and produced by Steinway Hamburg in 1909."
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