VOCAL IMPROVISATION FOR
INTERMEDIATE/EXPERIENCED

A DEEP DIVE IN THE PRACTICE OF COLLABORATIVE VOCAL IMPROVISATION
2-day intensive workshop with Alessio Castellacci
14-15 November, 2026 | Haacht (Leuven, BE)

This is a workshop for participants who are already familiar with singing and improvising, for voicers who feel confident working with pitch and rhythm, and for any musician who wishes to explore the deeper aspects of voice improvisation and vocal instant composition.
Over two days, we will explore Collaborative Vocal Improvisation in a small group of 8-10 people, balancing technique work with free explorations and ensemble journeys of spontaneous vocal pieces. Each participant will have the opportunity to receive individual coaching, and to experiment new approaches to find their unique signature of singing improvisation.

Collaborative Vocal Improvisation (CVI), is an art form - inspired by the work of Bobby McFerrin and Rhiannon a.o. - in which the music is co-created by the participants in real time through organised melodic/rhythmic patterns, starting from a common sonic vocabulary, a shared set of intentions, a guiding image or an agreed upon score. For me CVI is - at its core - the art of making choices by responding in a creative, connected, authentic way to the ever changing flow of the present moment. It is a contemplative and playful practice of resilience, of surrendering to the impulses of imagination, of trust in the connection with the others, of allowing a more kaleidoscopic sense of identity through the flow of music.

Some of the practices / singing games we’ll explore during the 2-day:
- different ensemble formats (solo, duet, trios, quintets)
- techniques to generate different types of vocal patterns - the basic components of CVI (melodies, rhythms, intuitive harmonisation)
- moving in between structured forms and more open, fluid forms
- improvising from language (invented language, somatic language)
- sound storytelling as a lens to develop a collective mind for musical cohesiveness
- image/theme based improvisation
- channeling songs of the moment
- enhancing emerging songs through body engagement

Overall, the exercises will be a space for each participant to tune in with their music sensitivity, to refine their singing vocabulary and strengthen the trust in their musicianship. We will practice how to be at service of the music of the moment, and to be in a gentle dialogue with the judgments or limiting believes that impedes our experience of musical flow. My approach to CVI grows out of the teaching of Rhiannon, Guillermo Rozenthuler and Roger Treece, and out of Bobby McFerrin's pioneering work. It is shaped as much by my background in contemporary dance, sound design and psychotherapy, and my personal experience with shamanic work and altered state of consciousness.

DATES : 14-15 November, 2026
SCHEDULE : Sat, Sun (10:00 - 17:00)
LIMITED NUMBER OF 10 PARTICIPANTS

FEE: €230
3 discounted places at €190 for students and people with financial need (just ask when you write us)

WHERE: we will be hosted in Karolien & Aart’s spacious living room (exact address will be given upon registration)
Haacht (10 minutes train from Leuven), Belgium

TO APPLY:
write to Alessio at info@the-world-is-sound.com
or contact Karolien — WhatsApp +32 485 69 31 10 / karolien_heyndrickx@hotmail.com

If you haven't worked with Alessio before, we'll ask you for two short, unedited recordings:
one minute of you improvising rhythmically, one minute melodically.
They're a way for Alessio to feel how you work with rhythm and pitch - so the group can work together with compatible skill levels.

Alessio Castellacci

>> Alessio Castellacci is a teacher of voice embodiment based in Berlin. He studied Developmental Psychology (La Sapienza University - Italy) and Choreography (Artez Institute – the Netherlands). He has worked since 2007 as a contemporary dancer, sound composer and voice mentor for various choreographers in Europe.
Since 2008 he has been dedicated to exploring the expressive possibilities of the human voice, and has since developed the pedagogical approach Embodied Voice Flow for voice & movement improvisation. 

For the last 20 years Alessio has been teaching regularly workshops in different venues in Europe (he has taught a.o. at Tanzhaus Zurich, Improspeckje Festival Zagreb, Altart Praha, Wasp Bucharest, Ials Rome, Kontakt Festival Budapest, Tanzfabrik Berlin, SMASH Berlin, NOW! Festival Berlin, ROAR Berlin, Dans Centrum Syd Malmö, Proda Oslo, Skolen for Samtidsdans Oslo, Dance Atelier Reykjavik, K3 Hamburg, Hzt Berlin, Choreography BA Rejkyavik, Dance BA Copenhagen, BARD College Berlin, University of Osnabrück and many others.
From 2012 to 2021 he has curated the educational program SMASH - now continued as ROAR Berlin - a yearly program for movement art. Since 2017 Alessio runs with voice artist and teacher Irena Z. Tomažin The World is Sound (TWIS), a platform for sound and voice practices based in Berlin. Alessio is a certified Estill Figure Proficiency (EFP) practitioner of the Estill Voice Technique, and a certified IFS (Internal Family System) Level 1 Practitioner.
Last year Alessio self-published his first book Cultivate Your Voice, a compendium of practices of voice embodiment and singing improvisation, and he is currently writing his second book The Rhizomatic Voice, which will be published in Spring 2027.

(photos ⓒ Florence Freitag)