Question: Illusion was a song that was played at the Eurovision contest held in what most populous city in Russia?

Context paragraphs:
Melodifestivalen 2011: Melodifestivalen 2011 was a Swedish song contest held between February and March 2011.  It selected Sweden's 51st song to represent Sweden in the Eurovision Song Contest, and was the 50th edition of Melodifestivalen.  Eric Saade, with the song "Popular", won the contest and thus was selected to represent Sweden in the 2011 Eurovision Song Contest.

Moscow: Moscow ( or ; Russian: Москва́ , "Moskva"; ] ) is the capital and most populous city of Russia, with 13.2 million residents within the city limits and 17.1 million within the urban area.  Moscow has the status of a Russian federal city.

Denmark in the Eurovision Song Contest 2009: Denmark participated in the Eurovision Song Contest 2009 held in Moscow on 16 May 2009.  Denmark was represented by Brinck with the song "Believe Again".  Two other Danish-born contestants also participated at the 2009 Eurovision contest: Susanne Georgi represented Andorra and Yohanna represented Iceland.

Latvia in the Junior Eurovision Song Contest: The participation of Latvia in the Junior Eurovision Song Contest first began at the inaugural Junior Eurovision Song Contest in 2003 which took place in Copenhagen, Denmark.  Latvijas Televīzija (LTV), a member of the European Broadcasting Union (EBU), were responsible for the selection process of their participation.  Latvia used a national selection format, broadcasting shows entitled ""Bērnu Eirovīzija"" and later ""Balss Pavēlnieks"", for their participation at the contests.  The first representative to participate for the nation at the 2003 contest was Dzintars Čīča with the song "Tu esi vasarā", which finished in ninth place out of sixteen participating entries, achieving a score of thirty-seven points.  Latvia were originally absent from the competition from 2006 to 2009 .  Latvia briefly returned in 2010 and 2011 however again withdrew from competing after the contest held in Yerevan, and have yet to make their return to the contest.

Romania in the Eurovision Song Contest 2015: Romania participated in the Eurovision Song Contest 2015 with the song "De la capăt" written by Călin Gavril Goia, Gabriel Constantin, Adrian Cristescu, Silviu-Marian Păduraru, Victor-Răzvan Alstani, Monica-Ana Stevens and Andrei-Madalin Leonte, and performed by Romanian band Voltaj.  The nation's broadcaster, Televiziunea Română (TVR), organised the "Selecția Națională 2015", a preselection show, in order to select the Romanian entry for the 2015 contest held in Vienna, Austria.  In a field of twelve songs, "De la capăt" emerged as the winner after scoring top marks from both a jury panel and a public televote.  While the track was performed at the Romanian national final in Romanian language, Voltaj finally decided to perform the song in a Romanian-English bilingual version at the Eurovision Song Contest.  The recording garnered press attention over Europe for its message, which refers to Romanians who have left their children in Romania in order to support them by working in other countries.  In the first of the Eurovision semi-finals, "De la capăt (All Over Again)" placed fifth out of the 16 participating countries, securing its place among the 27 other songs in the final.  In Romania's seventeenth Eurovision appearance on 23 May, "De la capăt" finished in fifteenth place, receiving 35 points.

Junior Eurovision Song Contest 2010: The Junior Eurovision Song Contest 2010 was the eighth edition of Junior Eurovision Song Contest and took place in Minsk, Belarus.  It was held on 20 November 2010.  The contest was won by Vladimir Arzumanyan from Armenia with the song Mama.  This gave Armenia its first Junior Eurovision victory and its first victory in any Eurovision contest.

Illusion (Krassimir Avramov song): "Illusion" is a song performed by Krassimir Avramov.  The song represented Bulgaria at the Eurovision Song Contest 2009 in Moscow, Russia.

Muusa: Muusa is the debut studio album by Estonian singer Laura Põldvere.  The album was released on the first of September, 2007 by Moonwalk studios.  It became one of the most successful albums in Estonia over the decade, selling over ten-thousand copies in 2007.  The song, "Moonwalk" was performed at the Estonian Eurovision contest in 2005, in hopes of representing Estonia during the Eurovision song contest, the song reached second place.  In 2007, Laura once again took part in the Eurovision song contest with the entry "Sunflowers".  The song came in third place.  Later that year, Laura's debut album "Muusa" was released, following the hit single, also named "Muusa".

Aven Romale: "Aven Romale" (Come in Gypsies), is a song by the Czech group Gipsy.cz that was the Czech entry at the 2009 Eurovision Song Contest held in Moscow, Russia.  It scored zero points at the Eurovision Song Contest semi-final, thereby failing to qualify for the final.

Romania in the Eurovision Song Contest 1994: 1994 was the debuting year of Romania at the Eurovision Song Contest at its second attempt, having previously failed to qualify from the semi-final stage of the Eurovision Song Contest 1993.  Televiziunea Română (TVR) held a national final to select the second Romanian entry for the Eurovision Song Contest held in Dublin, Ireland.  National final was won by Dan Bittman, with the song Dincolo de nori, music and lyrics by Antonio Furtuna & Dan Bittman.

Supporting paragraphs: Illusion (Krassimir Avramov song) Moscow
Answer: Moscow