Ad Libitum is an International Festival of Improvisation Art, initiated in 2006 by Krzysztof Knittel and organized by the Polish Music Council Foundation. Each edition focuses on a different genre of musical improvisation, ranging from jazz to the avant-garde performance techniques, free and conducted improvisation, open and graphic scores, as well as other related music streams, indeterminism and minimalism. The event explores the interaction of music with other forms of art – connections between sound, word, music and theatre in modern art movements and unconventional, interdisciplinary, and syncretic projects. It also initiated the encounters of key figures specializing in music and dance improvisation.

Guests invited to perform during the festival belong to the group of artists specializing in free improvisation, experimental art, computer and electronic music, musique concrete and contemporary jazz, such as Szabolcs Esztenyi, Zdzisław Piernik, Kazimierz Pyzik, Tomasz Stańko, Mieczysław Litwiński, Tadeusz Wielecki, Jerzy Kornowicz, Marek Chołoniewski, Olga Szwajgier, Jacek Kochan, Włodzimierz Kiniorski, Piotr Bikont, Tadeusz Sławek, Bogdan Mizerski, Mateusz Kołakowski, Marcin Dymiter, Cezary Duchnowski, Pierre Jodlowski, Michał Górczyński, Andrzej Izdebski, Rafał Mazur, Tetuzi Akiyama, Phil Niblock, Dieter Kaufmann, Ivo Medek, Markéta Dvořákova, Peter van Bergen, Alejandro Iglesias Rossi, Anthony Braxton, Misha Mengelberg, Han Bennink, Wolfgang Fuchs, Michel Doneda, Thomas Lehn, Anthony Pateras, Marina Rosenfeld, Raymond Strid, Ingar Zach, Jaap Blonk, Paolo Pandolfo, Maja Ratkje, Mats Lindström, Alexey Kruglov, Yuri Yaremchuk, Anat Pick and Valeri Scherstjanoi, and ensembles – the Mud Cavaliers, Kwartludium, Phonos ek Mechanes and Warsztat Muzyczny, John Tilbury and Eddie Prévosta from AMM, Andrei Smirnov with Moscow Laptops Cyber Orchestra, Company Blu, POW Ensemble and Marijan Ensemble.