To "trip the light fantastic" is to dance nimbly or lightly, or to move in a pattern to musical accompaniment. It is often used in a humorous vein. As early as 1908 it was viewed as a cliché or hackneyed phrase. Grammatically, it is an example of a constructionally idiosyncratic idiom, in that it is impossible to construct a meaningful literal-scene from the formal structure. As such it should be viewed as a catena.
History
This phrase evolved through a series of usages and references. The phrase is typically attributed to Milton's 1645 poem L'Allegro, which includes the lines
The imagery of tripping on toes also appears in Shakespeare's The Tempest: "Before you can say come, and goe, / And breathe twice; and cry, so, so: / Each one tripping on his Toe, / Will be here with mop, and mowe."
This expression became popular from the American song "Sidewalks of New York" (melody and text by Charles B. Lawlor and James W. Blake) in 1894. Part of the chorus: "Boys and girls together, me and Mamie O'Rourke / Tripped the light fantastic / On the sidewalks of New York."
Chester Himes uses a variation on the phrase: "Colored boys and girls in ski ensembles and ballet skirts were skating the light fantastic at two o'clock ... "
In 1967, English rock band Procol Harum released its hit song, "A Whiter Shade of Pale", with lyrics by Keith Reid, that included a play on the phrase with "skip the light fandango," casting Milton's light and nimble dancing in a modernist perspective.
More recent usage includes a line from Quentin Tarantino's movie Inglourious Basterds; a song title on electronica artist BT's debut album, Ima; Sophie Ellis-Bextor's 2007 album Trip the Light Fantastic; Mary Lou Lord's song, "Lights are Changing;" and The Light Fantastic, the second book in Terry Pratchett's Discworld series.