The ensemble consists of a group of freelance musicians, generally of 6-7 players of bowed and plucked strings and keyboards. But it is flexible in size, with the number of musicians and instrumentation always changing according to the repertoire. Thus, the ensemble has so far performed with only three musicians but also with up to twenty performers.

The repertoire of Simplicissimus mainly includes compositions from the second half of the 17th century and the first half of the 18th century. They play on period instruments, utilizing instrumental techniques that were not alien to the past centuries. The ensemble's aim is not only to restore the sound and performance style of the period, but also to make the music sound as revelatory in their performances as it did in its own time.

The name of the ensemble is a tribute to the German writer and composer Daniel Speer (1636-1707), who traveled in Upper Hungary and wrote a book about the practice of music in the Kingdom of Hungary, published under the pseudonym Ungarischer oder Dacianischer Simplicissimus. However, Speer also borrowed the name Simplicissimus from Hans Jakob Christoffel von Grimmelshausen's picaresque novel Der abenteuerliche Simplicissimus Teutsch. This work is set during the Thirty Years' War, with the protagonist traveling halfway across Europe and getting involved in a thousand adventures. The adventuring is also characteristic of this late successor of the baroque Simplicissimus: each performance of the ensemble is a great journey between eras, styles, and music of different nations.

The artistic director of this ensemble is violinist-musicologist Zsombor Németh.

Mensa Sonora et Al