The gigantic picture measures 31 feet 8 inches long and was commissioned by Seeger, for the music room at his New Jersey home. Seeger, who collected contemporary art, already owned six paintings by Lanyon.

The idea for the mural was to show the sea and myths associated with it such as the legend of the Golden Fleece.

As Lanyon explained: "The main appearance of it is as a fast-moving sea with cross-shore drift and counter drift." The artist began the painting in his St Ives studio and completed it on site, Debussy’s La mer inspiring him to phrase the work musically."

Also included in the show is the full size study for the mural which will be hung directly above, bringing these two important works together for the first time in forty six years. This will be the only opportunity to see them together.

To facilitate the first public showing of these works the Lanyon family has been very supportive of the exhibition. They are lending a number of seldom seen works, including preparatory drawings, correspondence relating to the mural, 3D constructions and a late partially completed work that sheds light on Lanyon’s working methods. These will give a very tight focus to the show, namely the last three years of the artist’s life, 1961-1964, when he took up gliding in order to be able to experience nature from the air.

Peter Lanyon (1918-64) was the only native-born Cornishman among the leading artists of the St Ives School. He taught at the Bath Academy of Art from 1952-57 and is remembered by former students for his unusual approach that involved exploring landscape from every conceivable angle.

In his work Lanyon rejected the conventions of the picturesque and instead evoked the more gritty working life of the Cornish industries, such as fishing, farming and mining. He died in 1964 from a blood clot following a gliding accident.

The Victoria Art Gallery, near Pulteney Bridge in Bath, is open Tuesday to Saturday 10am to 5pm, Sunday 1.30pm to 5pm. The Gallery is closed on Monday. Admission is free.