In May 1996 he appeared at the International Music Festival of Łańcut, Poland in the Sephardic Music Spectacle "W Drodze", for which he made the musical arrangements.
He is a founder member of Ensemble Antequera, which specialises in the performance of Medieval music from Spain. For this ensemble Genis produced two cd's.
Futhermore, he is a permanent member of Ensemble L'Alba, which concentrates amongst others on the music by the troubadours and trouvères. It is led by the leading specialist in this field, soprano Mikae Natsuyama.
More recently, Genis was asked to join the ensembles Super Librum (Jankees Braaksma) and Fala Musica (Maurice van Lieshout), whose repertories span the whole of the Middle Ages, with special attention for the songs in the Gruuthuse MS, which were recently made accessible to the general public by the Koninklijke Bibliotheek in The Hague.