Debussy Images pour Orchestre, in three movements written 1905-1912.
Filled with pride having finished his first book of Images for piano, Debussy began work almost immediately on a sequel, and in the same year, wrote to his publisher announcing his grand new idea, for a much larger ensemble; two pianos… 
Six months later, his enthusiasm still stayed strong, so much so that he began considering writing the work for an orchestra – with no less than quadruple woodwind, 4 horns, 4 trumpets, 3 trombones and tuba, 2 harps, celeste, a full string section and no fewer than 8 percussion instruments including castanets, xylophone and 3 tuned bells.
The first movement ‘Gigues’ was originally called Gigues Tristes, with inspriation from his memories of England. A Gigue was a baroque folk dance in a lilting double compound time, and for the melodies within, Debussy re-used the music from ‘Dansons la Gigue’ by his comtemporary Charles Bordes, and the tune of an older English folk song ‘The Keel Row’.  This in itself was a fashionable musical technique in England at the time, the country of inspiration for Debussy; take composers such as Ralph Vaughan-Williams and Gustav Holst for example – one of the most obvious examples being at the end of his second suite for military band – the Fantasia on ‘the Dargason’.
The second movement is the most famous by far, inspired by a different European country – Ibéria, the peninsula encompassing Spain, Portugal, Andorra and Gibraltar. Ibéria is in three sections, which translate to ‘Through the streets and the paths’, ‘The fragrance of the night’ and ‘The morning of a festival day’ all of which portray a day in a traditional Spanish town. The use of instruments such as castanets and muted trumpet give the movement a flamenco feel, used by many composers at the time in their own larger orchestral works – take Chabrier’s “España”, performed here by the Berlin Philharmonic under Plácido Domingo, and note the similarities in orchestration giving the distinctly Spanish feel.
Finally, Debussy finished his Images for Orchestra with the Round Dances of Spring – often considered one of his most modern works. In it, he takes two French folk tunes, much like in the first movement, and weaves them into the music, which also features an unusual 15/8 time signature. In the score, Debussy has added dotted lines to make the bars seem shorter and simpler, dividing them into groups of 3 and 2. When I say unusual… aside from Notes in Phantom of the Opera, the only other example of 15/8 I can find is in Medtner’s Night Wind Sonata, at the first subject here. You can see on the score that Medtner doesn’t divide the bars in the same way Debussy does – I would say in part because only one person plays a piano sonata, whereas, especially in Debussy’s case, a lot of people play in an orchestra.
Hope you found this interesting 🙂 There is so much to talk about with this amazing piece, and I’m in no way qualified to do it justice in this description; There are so many in-depth analyses of this and more of Debussy’s music online, both in written and video form, which I would encourage you to investigate if you are as interested as I am!
This description is my own, and feel free to quote and extract as much as you want for your own use – however I have used a few sources for information, especially regarding the history of the piece, which I have listed below.
- “Debussy’s Musical Gifts to Emma Bardac” by Robert Orledge (October 1974) from The Musical Quarterly magazine: https://academic.oup.com/mq/article-abstract/LX/4/544/1125479 – Emma Bardac was a singer at the time, who married Debussy in 1908, three years after he began writing the Images for Orchestra. If you have access, read the Oxford Academic article, or see this Wikipedia article to find out more about her, and her fascinating history with Debussy. (Spoiler alert: She was also involved with Fauré)
- “The Relationship between André Caplet and Claude Debussy” by Williametta Spencer (January 1980) from The Musical Quarterly magazine: https://academic.oup.com/mq/article-abstract/LXVI/1/112/1069475 – André Caplet was a contemporary of Debussy, and while he composed his own music, he also orchestrated many of Debussy’s piano works, such as The Martyr of St. Sébastien.
- Ok I’ll be honest, I might have accidentally clicked on Wikipedia to find this out, but the helpful author of the page has cited two articles behind paywalls:
- Pirie, Peter J. (1967). “Portrait of Debussy. 5: Debussy and English Music”. The Musical Times. 108 (1493): 599–601. doi:10.2307/953799. JSTOR 953799.
- Brown, Matthew (Autumn 1993). “Tonality and Form in Debussy’s Prélude à ‘L’Après-midi d’un faune“. Music Theory Spectrum. 15 (2): 127–143. doi:10.1525/mts.1993.15.2.02a00010. JSTOR 745811.