After receiving praise from important musicians like Julian Cope, Patti Smith and David Thomas from Pere Ubu, King Of The Opera completed two European Tours throughout Switzerland, Germany and France. The lead single "The Floating Song" from the album “Nothing Outstanding” was presented on the prestigious stage of the Ariston Theatre in Sanremo at the 2012 edition of Premio Tenco.
A lot of recognition also come from the world of cinema with the participation in various events of international significance such as Venice Film Festival, Milano Film Festival and Courmayer Noir Film Festival, also the song "Pink Clouds Over the Semipapero" is included in the soundtrack of the movie "La donna giusta" directed by Brando De Sica. In 2013 Mariotti had the chance to meet Patti Smith and play as opening act to her concert in Prato, Italy.
In 2017 he performed an acoustic solo set at the Hoxton Hall Theatre in London and in the same year he collaborated with the legendary Italian new wave band Diaframma for the song "Giorni".