Les Soirées de Nazelles, FP 84, is a set of variations for piano written by the French composer Francis Poulenc.
 During the evenings, the composer used to sit at the piano and improvise "portraits" of his friends, all based on a given theme.
 The work was begun in 1930, and completed at Noizay on October 1, 1936.
 At the beginning of the score, it reads:
The Duo Goebbels/Harth (1975–1988), combining German composer, music-theatre director and keyboardist Heiner Goebbels and German composer, multi-media artist and saxophonist Alfred 23 Harth became famous for its adaptation of and departure from European composers, especially Hanns Eisler, implemented in a provocatively fresh manner into structured free improvisations and deploying content from areas beyond music.
 The duo was nicknamed the “Eisler brothers” by music critic W.Liefland.
 They later also experimented with different genres and sound collages, including electronic devices.
 The duo played in many international festivals and concerts in cities as diverse as Tel Aviv, Zagreb, West and East Berlin and South America.
A Pseudoacid in Organic Chemistry is a cyclic oxocarboxylic acid.
 Most commonly, these form from aldehyde and keto carboxylic acids, and the cyclic forms are furanoid (5-ring with oxygen) or pyranoid (6-ring with oxygen).
 The original pseudoacid to be described as such (using the German "pseudosauren") was levulinic acid (4-oxopentanoic acid).
Jakob Ludwig Felix Mendelssohn Bartholdy (] ; 3 February 1809 4 November 1847), born and widely known as Felix Mendelssohn, was a German composer, pianist, organist and conductor of the early Romantic period.
X-Men: The Last Stand – Original Motion Picture Soundtrack was composed by John Powell and released on May 23, 2006 by Varèse Sarabande. ""
 was the third film in the series, and Powell was the third composer used.
 He came on the heels of John Ottman and Michael Kamen, both of which were criticized for their work on the scores.
Cyclic form is a technique of musical construction, involving multiple sections or movements, in which a theme, melody, or thematic material occurs in more than one movement as a unifying device.
 Sometimes a theme may occur at the beginning and end (for example, in Mendelssohn's A minor String Quartet or Brahms's Symphony No. 3); other times a theme occurs in a different guise in every part (e.g. Berlioz's "Symphonie Fantastique", and Saint-Saëns's "Organ" Symphony).
Heinrich Schütz (] ; 18 October [O.S. 8 October] 1585 – 6 November 1672) was a German composer and organist, generally regarded as the most important German composer before Johann Sebastian Bach and often considered to be one of the most important composers of the 17th century.
 He wrote what is traditionally considered to be the first German opera, "Dafne", performed at Torgau in 1627, the music of which has since been lost.
Carl Heinrich Graun (7 May 1704 – 8 August 1759) was a German composer and tenor singer.
 Along with Johann Adolph Hasse, he is considered to be the most important German composer of Italian opera of his time.
Cassiber were a German avant-rock group founded in 1982 by German composer and saxophonist Alfred Harth, German composer, music-theatre director and keyboardist Heiner Goebbels, English drummer Chris Cutler from Henry Cow and German guitarist Christoph Anders.
 They recorded five albums, toured extensively across Europe, Asia and North America, and disbanded in 1992.
Leon Jessel, or Léon Jessel (January 22, 1871 – January 4, 1942) was a German composer of operettas and light classical music pieces.
 Today he is best known internationally as the composer of the popular jaunty march "The Parade of the Tin Soldiers", also known as "The Parade of the Wooden Soldiers".
 Jessel was a prolific composer who wrote hundreds of light orchestral pieces, piano pieces, songs, waltzes, mazurkas, marches, choruses, and other salon music.
 He achieved considerable acclaim with a number of his operettas — in particular "Schwarzwaldmädel" ("Black Forest Girl"), which remains popular to this day.

Question: Which German composer used cyclic forms in their pieces?
Answer: Jakob Ludwig Felix Mendelssohn Bartholdy