As a cello player, he is a much sollicited guest musician for other artists and music groups, often together with his brother Buni Lenski. In 2004 he set up a collaboration with Swiss avant-garde cello player Bo Wiget. Together they released an album Die Vögelein schweigen im Walde.
In 2008 Simon Lenski composed the soundtrack for the movie Left Bank Linkeroever.
Simon Lenski composed the music for several theater plays.
In 2011 Simon Lenski composed and recorded the soundtrack for the short movie Motor of Dutch movie maker Simone Bennett. For this musical piece a special electric twelve string violin was built for him by experimental luthier Yuri Landman.
For Simon Lenski's discography with DAAU, please see DAAU.
- Simon Lenski / Bo Wiget - Die Vögelein schweigen im Walde (2007)
- Laïs Lenski - Laïs Lenski (2009), together with Laïs
- Simon Lenski: Oh City (solo EP 2016) Simon Lenski
- Kiss My Jazz
- Bettie Serveert
- Think Of One
- Flowers for Breakfast
- Mintzkov Luna
- Donkey Diesel
- Mauro - Songs from a Bad Hat
- Zita Swoon
- Maxon Blewitt
- An Pierlé
- Soul Sucker
- I Hate Camera
- Paramount Styles
- Ellen Schoenaerts Kwartet
- Magnus (band)
- Gorki / Luk De Vos
Film and theatre scores
- Wunderbaum / Venlo, Theatre Score
- Wunderbaum / The Haunted House Of History, Theatre Score and performer
- Damaged Goods / Meg Stuart : Revisited, performer
- Eisbär / Collateral Damage, Theatre Score
- Andcompany & Co / Der (kommende) Aufstand, performer
- Andcompany & Co / Orpheus in der Oberwelt, Theatre Score / performer
- "Theater Froefroe / Macbeth, Theatre Score and performer
- Left Bank Linkeroever, soundtrack
- Waste Land, soundtrack
- Needcompany / O, Or The Challenge Of This Particular Show Was To Have Words Ending In O , Performer / Theatre Score
- Benny Claessens & CAMPO/ Hello Useless, for W and friends, Theatre Score
- Wunderbaum / The Future Of Sex , Theatre Score / Performer