Gnossienne No 1, arranged for Viola & Piano. The Gnossiennes, are several piano compositions written by the French composer Erik Satie in the late 19th century. The works are for the most part in free time (lacking time signatures or bar divisions) and highly experimental with form, rhythm and chordal structure. The form as well as the term was invented by Satie. Satie's coining of the word gnossienne was one of the rare occasions when a composer used a new term to indicate a new "type" of composition. Satie used many novel names for his compositions (vexations, croquis et agaceries and so on). Ogive, for example, is the name of an architectural element which was used by Satie as the name for a composition, the Ogives. Gnossienne, however, was a word that did not exist before Satie used it as a title for a composition. The word appears to derive from gnosis. Satie was involved in gnostic sects and movements at the time that he began to compose the Gnossiennes. However, some published versions claim that the word derives from Cretan "knossos" or "gnossus"; this interpretation supports the theory linking the Gnossiennes to the myth of Theseus, Ariadne and the Minotaur. Several archeological sites relating to that theme were famously excavated around the time that Satie composed the Gnossiennes.

It is possible that Satie may have drawn inspiration for the title of these compositions from a passage in John Dryden's 1697 translation of the Aeneid, in which it is thought the word first appeared. The Gnossiennes were composed by Satie in the decade following the composition of the Sarabandes (1887) and the Trois Gymnopédies (1888). Like these Sarabandes and Gymnopédies, the Gnossiennes are often considered dances. It is not certain that this qualification comes from Satie himself – the sarabande and the Gymnopaedia were at least historically known as dances.

The musical vocabulary of the Gnossiennes is a continuation of that of the Gymnopédies (a development that had started with the 1886 Ogives and the Sarabandes) later leading to more harmonic experimentation in compositions like the Danses gothiques (1893). These series of compositions are all at the core of Satie's characteristic late 19th century style, and in this sense differ from his early salon compositions (like the 1885 "Waltz" compositions published in 1887), his turn-of-the-century cabaret songs (Je te veux), and his post-Schola Cantorum piano solo compositions, starting with the Préludes flasques in 1912. These Three Gnossiennes were composed around 1890 and first published in 1893. A revision prior to publication in 1893 is not unlikely; the 2nd Gnossienne may even have been composed in that year (it has "April 1893" as date on the manuscript). The piano solo versions of the first three Gnossiennes are without time signatures or bar lines, which is known as free time.

These Gnossiennes were first published in Le Figaro musical No. 24 of September 1893 (Gnossiennes Nos. 1 and 3, the last one of these then still "No. 2") and in Le Cœur No. 6–7 of September–October 1893 (Gnossienne No. 2 printed as facsimile, then numbered "No. 6").

The first grouped publication, numbered as known henceforth, followed in 1913. By this time Satie had indicated 1890 as composition date for all three. The first Gnossienne was dedicated to Alexis Roland-Manuel in the 1913 reprint. The 1893 facsimile print of the 2nd Gnossienne contained a dedication to Antoine de La Rochefoucauld, not repeated in the 1913 print. This de La Rochefoucauld had been a co-founder of Joséphin Péladan's Ordre de la Rose-Croix Catholique et Esthetique du Temple et du Graal in 1891. By the second publication of the first set of three Gnossiennes, Satie had broken already for a long time with all Rosicrucian type of endeavours.

Also with respect to the tempo these Gnossiennes follow the Gymnopédies line: slow tempos, respectively Lent (French for Lento/slow), avec étonnement ("with astonishment"), and again Lent.

A sketch containing only two incomplete bars, dated around 1890, shows Satie beginning to orchestrate the 3rd Gnossienne.

The first and third Gnossiennes share a similar chordal structures, rhythm and share reference to each other's thematic material.