On a choir tour in 2000, Aventura performed medieval music for the first time, wearing borrowed costumes at the Bornholm Medieval Centre. This was the start of a major interest in the period and its music; an interest that has put Aventura in a class of its own: Medieval and Chamber choir in one.
While most people recognise the sound of gregorian chant, the greater part of polyphonic music is much less known and can at first seem weird and exotic. It has a lot in common with certain 20th Century compositions, for example as regards the unresolved dissonant chords. Several modern composers have also been inspired by medieval music.
Aventura's music varies from anonymous unison and two-part arrangements, to more complicated three- and four-part settings; from peaceful and meditative to rhythmic and dance-like. The later music is from composers such as Perotin, Leonius and Machaut. Aventura provides music from the medieval period from 1000 to 1500, originating from various different European countries.
The repertoire is mostly religious; both music originating from church/chapel usage, and other pieces with a general religious content. Religion was so much a part of daily life in the 14th Century, that many ordinary songs had a religious theme, or had a couple of verses directed to one of the saints, and another verse about something more down-to-earth. The decision to adopt the role of monks and nuns is both due to the more religious musical settings, but also because a large group of singers in the Middle Ages would not occur outside a cloister setting. Aventura has non-religious music in its repertoire, and performs this in smaller groups and different costumes.
Some of the music is accompanied by sinfonia and/or drum. The sinfonia is a kind of hurdy-gurdy with one melody string and two drones and has been constructed according to a picture from the 14th Century.