Hashtag Ensemble is a music cooperative founded by flutist Ania Karpowicz in 2013 and associating 20 young performers and composers focused on the performance of 20th and 21st century music.

The #WITKACY program was created in 2017 for photo scores at the invitation of the Polish Contemporary Music Society. The album is a record of the premiere concert that took place in the PROM Kultury in Warsaw. The band performed with the same program at the M. Karłowicz Philharmonic in Szczecin as part of the SOUNDLAB (2018) series.

Working in improvisation collectives is one of the main activities of the Hashtag Ensemble, which is reflected in the first album of the band "Visegrad Songs" (2015) containing reinterpretations of the songs of Karłowicz, Bartok, Bella and Dworzak. The material from the album "V4" played at the POLIN Museum of the History of Polish Jews, at Solti Hall in Budapest, the National Philharmonic in Minsk, as well as at the music clubs Meskalina (Poznań) and Boogaloo (Warsaw). The group also improvised to the motifs of Bela Bartok's "Concerto For Orchestra" in the Polish Radio at the W. Lutosławski Concert Studio in Warsaw and constantly cooperates with the Center for Contemporary Art at Ujazdowski Castle in Warsaw, improvising to graphic scores at exhibitions of visual artists (El Sy, Laura Lima, Assaf Gruber, J.J. Ziółkowski and others).