specialises in the performance of contemporary and early music. The ensemble has performed notably at the Skálholt Summer Concerts Festival (Iceland), Sönghátíð í Hafnarborg Festival (Iceland), Early Music Festival in Haapsalu (Estonia), Witold Lutosławski Concert Studio of the Polish Radio, Arvo Pärt Centre in Laulasmaa (Estonia), Musiikkitalo Music Centre (Helsinki), and many other venues. 

Simultaneo has premiered many new works by composers such as Anna Rocławska-Musiałczyk, Uģis Prauliņš, Alberto Schiavo, and Aleksandra Vrebalov. The ensemble collaborates with many outstanding instrumentalists including Krzysztof Urbaniak (organ), Maria Pomianowska (lap fiddle), Irek Wojtczak (saxophone), Mirosław Pachowicz (bassoon), Maja Miro (transverse flute), Danuta Zawada (Baroque violin), Małgorzata Skotnicka (harpsichord), Weronika Kulpa (Baroque cello), and Maksym Zajączkiewicz (spinet). February 2024 saw the premiere of an album recorded for Polish Radio, Nowe oblicza tradycji (New Faces of Tradition), featuring commissioned works for Biłgoraj suka and vocal octet by contemporary composers. The recording also features Maria Pomianowska as soloist and Karol Kisiel as conductor. In addition to its concert activities, Simultaneo is also involved in educational events, with particular focus on masterclasses for young musicians. During these, the ensemble has collaborated with outstanding artists such as Jaan-Eik Tulv and Vox Clamantis, Daniel Reuss, Risto Joost, Johannes Knecht, and Signe Asmussen. The founder and artistic director of Simultaneo is Karol Kisiel.