This innovative orchestra, dedicated to authentic re-creations of seventeenth, eighteenth, and nineteenth century music on historically appropriate instruments has in several projects created to modern ears what are radically unexpected orchestral timbres not experienced since the original period in which the works were composed. In their musicology, methods of working and evolution, and their artistry, this internationally renowned group is unique. Following the vision of its permanent musical director Jos van Immerseel, the orchestra developed from an initially small chamber ensemble of six players brought together in 1985 to study the works of Bach. In 1987, the group was enlarged to an ensemble of 17 players who concentrated on music of the Baroque era. In 1988, the group played for the production of Rameau's Pygmalion at the Opéra de Versailles. By 1989, the group had expanded to 25 musicians who performed Viennese Classical repertoire. From 1990 to 1992, the group focused on the complete series of Mozart's piano concerti. Progressing historically, the group then evolved into a symphonic orchestra typical to the Romantic era with an average of 45 players and a repetoire encompassing the early nineteenth century embodied in the works of composers such as Beethoven, Mendelssohn, Niels Gade, and Rossini. In 1993, the orchestra performed in Rossini's Othello, and during the 1995-1996 season of the Flemish Opera, it played in Handel's Xerxes. The musicians, from Europe, the U.S., Australia, and Japan, meet for three or four weeks, five or six times annually, to prepare and perform a program based on their own preferences, with parts and interpretative notes given far in advance of the date. Since 1996, the orchestra has benefited by researches into manuscripts and other source materials undertaken by the publishing house Bärenreiter Verlag. One of the Anima Eterna's most striking achievements was the 1996-1997 cycle of the complete Schubert symphonies on the original instruments, which created a sensation when audiences heard the fresh and dramatic tone colors intended by the composer. Anima Eterna's 1997 season revealed the orchestra's mastery of the compositions of Franck and Saint-Saëns. In 1998, the orchestra immersed itself in the exploration of the symphonies of Beethoven.