Question: How many dance music does the writer of Gross-Wien Op. 440 composed?

Context paragraphs:
Dance music: Dance music is music composed specifically to facilitate or accompany dancing.  It can be either a whole musical piece or part of a larger musical arrangement.  In terms of performance, the major categories are live dance music and recorded dance music.  While there exist attestations of the combination of dance and music in ancient times (for example Ancient Greek vases sometimes show dancers accompanied by musicians), the earliest Western dance music that we can still reproduce with a degree of certainty are the surviving medieval dances.  In the Baroque period, the major dance styles were noble court dances (see Baroque dance).  In the classical music era, the minuet was frequently used as a third movement, although in this context it would not accompany any dancing.  The waltz also arose later in the classical era.  Both remained part of the romantic music period, which also saw the rise of various other nationalistic dance forms like the barcarolle, mazurka, ecossaise, ballade and polonaise.

Underground dance music: The term underground dance music (short version in music jargon: UDM) has been applied to artistic dance music movements, such as early 1970s disco and 1980s Chicago house, but the term has since then come to be defined by any electronic dance or house music artist/band that avoids becoming a trend/mainstream nowadays.  Other early "underground dance music" artists include Little Louie Vega, Tony Humphries, Larry Levan, David Mancuso, Frankie Knuckles, Nicky Siano, Lenties Deep and many others.  In the late 1970s, the term underground dance music was associated with the music initially played at places like Paradise Garage, The Loft and The Warehouse.

Loopmasters: Loopmasters is an English sound design record label based in Brighton, England.  Loopmasters release and publish sample packs on the pro-audio market and cooperate with major software and hardware vendors including Ableton Live and Focusrite.  Since 2008 Loopmasters also functions as an online store for music composers, and computer-based DAWs like Steinberg Cubase, Apple Logic, Propellerheads Reason or Ableton Live.  Loopmasters populated the market of pro-quality sound design and was among the first to release samples from renowned performers, producers and DJs such as Deadmau5, Re-Zone, Coldcut, Full Cycle, Mad Professor, Meat Katie, Todd Terry, Ray Keith, DJ Pierre and many dance music icons.

Gross-Wien: Gross-Wien Op. 440 is a waltz by Johann Strauss II written in 1891 and was a choral waltz for the Wiener Männergesang-Verein (Vienna Men's Choral Association) during the Vienna Fasching (Carnival) of the same year.  The text for the choral version of the waltz was by Franz von Gernerth.

Johann Strauss II: Johann Strauss II (October 25, 1825 – June 3, 1899), also known as Johann Strauss Jr., the Younger, the Son (German: "Sohn" ), Johann Baptist Strauss, was an Austrian composer of light music, particularly dance music and operettas.  He composed over 500 waltzes, polkas, quadrilles, and other types of dance music, as well as several operettas and a ballet.  In his lifetime, he was known as "The Waltz King", and was largely then responsible for the popularity of the waltz in Vienna during the 19th century.

Finally (CeCe Peniston song): "Finally" is a 1991 song by American musician CeCe Peniston from her debut album, "Finally".  A dance mix of this song was made, and this remixed version was used in many dance music compilations.  "Finally" became Peniston's first (and biggest) hit song, peaking at number five on the US Hot 100 in January 1992 and becoming her only US top-ten hit to date.  Prior to that, it was also successful on the US Dance chart, where it spent two weeks at number one in late 1991.  In addition, the song peaked at number two on the UK Singles Chart in a remixed version.

Eric Singleton: Eric XL Singleton (born Eric Newkirt Singleton, November 6, 1968, New York City), also known as XLarge, is an American rapper who has appeared on many dance music productions, significantly on Modern Talking songs, such as "You're My Heart, You're My Soul '98", "China In Her Eyes", and "Last Exit to Brooklyn".

Cabbage patch dance: The cabbage patch dance is a dance involving putting the hands together in the form of fists and moving them in a horizontal, circular motion.  The Gucci Crew II had a song describing the dance, as well as Dr. Dre and DJ Yella (of the rap group N.W.A.) in 1987.  The dance they made was featured in the song "The Cabbage Patch."  It soon became very popular, showing up in many dance clubs in America.  The dance's name is derived from the popular line of dolls "The Cabbage Patch Kids" or the use of "cabbage" as slang for paper money.  There are many on-line videos showing how to do the dance.  The dance was originally celebratory and often associated with sports achievements or victories.

Liu Yan (dancer): Liu Yan is a classical Chinese dancer.  She has performed in many dance dramas and won many dance competitions in and outside China.

Country-western dance: Country/western dance, also called Country and Western dance, encompasses many dance forms or styles, which are typically danced to country-western music, and which are stylistically associated with American country and/or western traditions.  Many of these dances were "tried and true" dance steps that had been "put aside" for many years, and became popular under the name(s) "country-western", "cowboy", or "country".

Supporting paragraphs: Gross-Wien Johann Strauss II
Answer: over 500