free concerts and opera galas in unconventional venues (such as the port of Piraeus for a "waltz of the ferry boats", the Athens International Airport, the metro stations, the popular Varvakeio central market, or the esplanades of the Athens National Archaeological Museum or of the New Acropolis Museum, etc.). Other initiatives included the programs "Suitcase Opera" (operas in miniature form performed in Greek peripheral cities) and "Opera Bus" (double-decker bus on which the singers of the Opera company performed to passers-by in the streets of Athens), the establishment of a "GNO Children’s Chorus" (of about 80 members, which sung for US president Barack Obama at the occasion of his official visit to Athens in 2016) and of a "Young Artists Program", and a participation to the EU outreach program "Interactive Opera for Primary Schools", which concerned 45,000 pupils in 147 schools in Greek regions. In parallel, Michailidis developed a framework for international co-productions with large lyrical theaters such as the Royal Opera House of Covent Garden in London, the Welsh National Opera, the Vienna State Opera, the Arena di Verona Festival, the Teatro La Fenice in Venice. He also deepened and extended GNO's relations with other European theaters as a member of the European Forum of Lyrical Theaters, Opera Europa. Artistically, Michailidis conducted many opera performances within the walls of GNO's historic building (Olympia Theater, 700 seats), in the open-air antic Herodes Atticus Theater (under the Acropolis, 5,000 seats) during the annual summer's Athens Festival and in the two halls of the Megaro Mousikis (Athens Concert Hall, 2,000 & 1,750 seats), with a majority of representations sold out. He conducted Les contes d'Hoffmann (2001), L'elisir d'amore (2002), Fedora (2002), Tosca (2004 & 2012), Il Trovatore (2005), L'italiana in Algeri (2006), La Traviata (2010), Die Zauberflöte (2010 & 2011), Faust (2012), I vespri siciliani (2013), Madama Butterfly (2013), Macbeth (2014), Otello (2014), La Bohème (2015), Tristan und Isolde (2015), Aida (2016) and Lohengrin (2017). GNO's repertoire was significantly increased and proposed 35 new opera and operetta titles, as well as 11 new ballets. Michailidis also continued to champion the production of rare works and of contemporary music. Notably, he produced stage performances of contemporary works composed by 6 Greek modern composers, and in 2014, the creation in world's premiere of the contemporary Opera The Murderess (Η Φόνισσα, based on the famous novel by Alexandros Papadiamantis) written by Giorgos Koumendakis, GNO's "composer