In the season 2019/20 made his successful debut as RIGOLETTO at the Würzburg Theatre and impressed as JUAN PERON in “Evita”. Previously, he could be seen here as the MUSIC TEACHER in “Ariadne auf Naxos”, as GUNTER in “Götterdämmerung” and as PETER BESENBINDER in “Hänsel und Gretel”. In the season 21/22 he is GIANNI SCHICCHI here and PRUS in “The Makropulos Case”

In the season 18/19 he impressed as SCARPIA in “Tosca” at the Kilden Opera Kristiansand. Further international engagements brought the Swedish baritone to the Frankfurt Opera and the Wiesbaden State Theatre as PAOLO ALBIANI in “Simon Boccanegra”, as SCHAUNARD in “La Bohème” and as MICHELE in Puccini’s “Il Tabarro” to the Gothenburg Opera, as GIANNI SCHICCHI and GUGLIELMO WULF in Puccini’s “I Villi” to the Latvian National Opera in Riga, as MONTERONE in “Rigoletto” and SCARPIA in “Tosca” to the Malmö Opera, as MEFISTO in “Faust” and JAGO in “Otello” to the die Norrlandsoperan and as ESCAMILLO in “Carmen” to the Folksoperan Stockholm.

For his JAGO in ‘Otello’ at the Norrlands opera he was nominated ‚Singer of the year‘ by the German magazine Opernwelt. Kosma Ranuer sang the role of AXEL OXENSTIERNA in Foroni’s “Cristina, Regina di Svezia”, which was broadcasted all over Europe and released on CD (Sterling Label).

In 2014 the artist debuted as STANKAR in Verdi’s “Stiffelio” at the Stockholm Royal Opera, which was followed by a concert tour with the Norrlands Operan at the occasion of their 40th anniversary.

Kosma Ranuer studied at the University College of Opera in Stockholm. In 2007 he was a finalist at the Belvedere Vocal Competition in Vienna.​

Lately, Kosma Ranuer sang with huge success first roles of the German repertoire. He portrayed KASPAR in “Der Freischütz” at the Rostock Popular Theatre and at the Immling Music Festival and BILL in “Rise and Fall of the City Mahagonny” at the Norrlandsoperan. He was PIZARRO in concert performances of “Fidelio” and was ALBERICH in “Götterdämmerung” under the musical direction of Maestro Joana Mallwitz in Riga. At the Folksoperan Stockholm and at the Opera Festival at the Amphitheatre in Plovdiv, Capital of Culture 2019, he knew huge successes in the title role of Wagner’s DER FLIEGENDE HOLLÄNDER.

The Austrian magazine Der Neue Merker wrote in June 2016:
With an exceptionally beautiful voice, depth and brightness and arespectful scenic portrayal the contradictory and versatile image of the Dutchman was masterly realized by the Swedish baritone KOSMA RANUER.. His appearance from the upper ranges of the amphitheatre was so strong, he was able to capture the attention of the entire audience.

In 2021 he sang a gala concert with the Opera Østfold in Ford Fredriksten At this stage, which is the largest open air stage in Norway, he portrays the title part in “Der Fliegende Holländer” in 2022.