The heart of the tango study programme is formed by the tango orchestra OTRA (Orquesta Tanguera de Rotterdam Integrada por Alumnos) and the Tango Orchestra Class. The Tango Orchestra Class is meant for all instrumentalists with the exception of guitarists. For them the guitar ensemble ‘Guitarras Porteñas’ forms the focal point of the study programme. The program consists of traditional tango's and genre-related rhythms (milonga ciudadana, milonga campera, vals criollo) as well as connections with contemporary genres.
Apart from the work of the orchestra's of Osvaldo Pugliese (who was the artistic leader of the Argentinian Tango department of the Rotterdam WorldMusic Academy of the Rotterdam Conservatory/Codarts), Aníbal Troilo, Carlos Di Sarli and Horacio Salgán, there are also young Argentinian composers who write music for OTRA. Like Sonia Possetti, Alejandro Schwarz and Gustavo Gancedo.
The orchestra is led by Leo Vervelde and consists of students and teachers from the Tango department. Over the years, OTRA has performed in Spain, Germany, Belgium and France. In 2006 OTRA participated in the 'VII festival Buenos Aires Tango' in Argentina and one of their concerts was en still is being broadcast live on the Argentinian television.