Theodore Parker is a guitarist, electro-acoustic musician, and improviser. He has created improvised music for dance, performance installations, and theatre. He currently pursues Phd studies at the Estonian Academy of Music and Theatre.

Jaanus Siniväli is creator of contemporary multidisciplinary pieces, double bass player and electronic musician.

He is active in playing contemporary music and free improvisation. His main performance setups include double bass, DIY based modular synthesizer and double bass with foot controllable modular synthesizer. Interest in western and eastern practice of thinking has led to a search for function of music and arts which is manifested in Metaphysical Studies series in the form of performances and text scores. From there comes the curiosity to find solutions to situations where function of music is altering or unknown which has resulted in the use of sound in fixed free improvisation and game set-ups. As well as work in multidisciplinary collaborations consisting either sound and text, -movement, - visuals or video.

He finished CoPeCo international masters program in 2018 where he worked on a project combining sound, movement and visuals in an environment of fixed improvisation. He is active in Estonian Society of Electronic Music (EES) and co-organizer of Helikoosolek sound gatherings in Tartu.

Improtest is concert series that brings improvisational music from local and foreign authors to local audience. The concerts have been taking place since 2005 once a month.