On Wikipedia https://en.wikipedia.org/wiki/Sequentia_(music_group)
Creation 1977
City Basel, Switzerland
Country Switzerland
Links Allmusic

Sequentia is an early music ensemble, founded in 1977 by Benjamin Bagby and Barbara Thornton (died 8 November 1998). The group specializes mainly in Medieval music. Sequentia focuses particularly on music with texts, specifically chants and other stories with music, such as the Icelandic Edda. They are interested in the interplay between drama and music, and sometimes do partially staged performances, such as that of Hildegard of Bingen's Ordo Virtutum. Bagby and Thornton have both been active in original research on the projects they perform.

Originally formed in Basel in 1977, the group moved to Cologne, Germany, in the same year (Neumann 1999; Zahn 2001). The group would work from Cologne for more than twenty years; in 2002, it relocated to Paris.

In 1977, while still at Basle, Thornton and Bagby, together with the group Studio der frühen Musik and some associated singers, staged two 12th century miracle plays relating to St Nicholas; the plays were taken on tour and a live recording from a performance in Amsterdam was put out the following year on an LP entitled Ludi Sancti Nicolai ("Plays of St.Nicholas"; EMI Electrola, 1978). Although the singers involved used the name "Ensemble Vocale Guillaume Dufay", this experimental staging of two church dramas can be regarded as the debut record of Sequentia; the dramatic and angular vocal style and the approach to partly improvised instrumentation already has much in common with their later recordings.

The only long-term members of Sequentia have been Benjamin Bagby, Barbara Thornton, Norbert Rodenkirchen, and Katarina Livljanic after Thornton's death. Margriet Tindemans was a member for the first nine years of the group's existence (Bagby 2015). Tenor Wolodymyr Smishkewych has sung with several projects since 2000. The rest of the members are hired according to the needs of the particular project.

They mainly record on the Deutsche Harmonia Mundi label (Weber 2001). Wikipedia