Question: In what city was Symphony No. 13, which was mistaken at one time to be created by the Father of the Symphony, written?

Context paragraphs:
Internet Symphony No. 1: The Internet Symphony No. 1 - "Eroica", is a piece written by the Chinese composer Tan Dun for the YouTube Symphony Orchestra.  It was the first of such events where musicians around the world play the same piece virtually via the internet, and the best performers selected were arranged into an internet symphony orchestra, featured on YouTube.  In addition to submitting a performance of the Internet Symphony No.1 ("Eroica"), musicians were also allowed to submit a video of themselves playing one of the other selected pieces.  The best performers were invited to play at New York City's Carnegie Hall on April 15, 2009, with all expenses paid by YouTube.  Winners were decided by the most number of votes cast by YouTube users.

Jena Symphony: The so-called "Jena Symphony" is a symphony that was at one time attributed to Ludwig van Beethoven.  The symphony was discovered by Fritz Stein in 1909 in the archives of a concert society in Jena, from which it derived its name.  Stein believed it to be the work of Beethoven and it was so published by Breitkopf und Härtel in 1911.  It is now known that the piece was the work of Friedrich Witt (born the same year as Beethoven).

Joseph Haydn: (Franz) Joseph Haydn ( ; ] ; 31 March 173231 May 1809) was an Austrian composer of the Classical period.  He was instrumental in the development of chamber music such as the piano trio and his contributions to musical form have earned him the epithets "Father of the Symphony" and "Father of the String Quartet".

Symphony No. 13 (Michael Haydn): Michael Haydn's Symphony No. 13 in D major, Perger 37, Sherman 13, MH 132, believed to have been written in Salzburg in 1768, was at one time mistaken for a symphony by Joseph Haydn (Hob.  I:D26).

London Schools Symphony Orchestra: The London Schools Symphony Orchestra (LSSO) is a symphony orchestra with musicians drawn from students in London schools, and featuring professional conductors and soloists.  It was founded in 1951.  Its founder and original director was the late Dr Leslie Russell, at one time assisted by Niso Ticciati.  From 1990 until 2001 the artistic director was Oliver Butterworth.  The current artistic director is American conductor/composer Peter Ash.

Symphony No. 7 (Michael Haydn): Michael Haydn's Symphony No. 7 in E major, Perger 5, Sherman 7, MH 65, written in Salzburg in 1764, is one of the few symphonies in E major written in the 18th century, and was the first of four symphonies in the key to be mistaken for a symphony by Joseph Haydn (Hob.  I:E1).

Harmonium (Adams): Harmonium is a composition for chorus and orchestra that could be considered a choral symphony in all but name, by the American composer John Adams, written in 1980-1981 for the first season of Davies Symphony Hall in San Francisco, California.  The work is based on poetry by John Donne and Emily Dickinson.  It is regarded as one of the key compositions of Adams' "minimalist" period.  The San Francisco Symphony and the San Francisco Symphony Chorus, with conductor Edo de Waart, gave the premiere of the work on 15 April 1981, and subsequently recorded it.  The UK premiere was on 13 October 1987 at Birmingham Town Hall, with the City of Birmingham Symphony Orchestra (CBSO) conducted by Simon Rattle.  Rattle and the CBSO gave the London premiere on 28 July 1990 at The Proms.

Unfinished symphony: An unfinished symphony is a fragment of a symphony, by a particular composer, that musicians and academics consider incomplete or unfinished for various reasons.  The archetypal unfinished symphony is Franz Schubert's Symphony No. 8 (sometimes called "Schubert's Unfinished Symphony"), written in 1822, six years before his death.  It features two fully orchestrated movements.  While it seems clear from sketches that Schubert set out to create a traditional four-movement symphony, this has been the subject of endless debate.  Schubert wrote the symphony for the Graz Musical Society, and gave the manuscript to his friend Anselm Hüttenbrenner, in his capacity as its representative.  However, Hüttenbrenner did not show the score to the society at that time, nor did he reveal the existence of the manuscript after Schubert died in 1828, but kept it a secret for another 37 years.  In 1865, when he was 76 (three years before his death), Hüttenbrenner finally showed it to the conductor Johann von Herbeck, who conducted the extant two movements on 17 December 1865 in Vienna, adding the last movement of Schubert's third symphony as the finale.  Music historians and scholars then toiled to "prove" the composition was complete in its two-movement form, and indeed, in that form it became one of the most popular pieces in the late 19th century classical music repertoire, and remains one of Schubert's most popular compositions.

Symphony No. 12 (Michael Haydn): Michael Haydn's Symphony No. 12 in G major, Perger 7, Sherman 12, MH 108, written in Salzburg in 1768, was at one time mistaken for a symphony by Joseph Haydn (Hob.  I:G8).

Symphony No. 14 (Michael Haydn): Michael Haydn's Symphony No. 14 in B-flat major, Perger 52, Sherman 14, MH 133, was written in Salzburg between 1768 and 1770 For some reason Lothar Perger believed it to be the last symphony Michael Haydn ever wrote.  This work was at one time attributed to Joseph Haydn, the third work in B-flat major so attributed.

Supporting paragraphs: Symphony No. 13 (Michael Haydn) Joseph Haydn
Answer: Salzburg