A music cooperative founded in 2013 and led by flutist Ania Karpowicz. The group brings together outstanding young musicians and composers. It has premiered 259 new works and received 180 awards from competitions for classical and contemporary music performers. The ensemble forms egalitarian structures based on the multifaceted activities of its members and on programming rooted in distinct, mostly extramusical contexts. 

Hashtag Ensemble performs at festivals of classical and contemporary music. Its repertoire comprises twentieth-century classics: Peter Maxwell Davies, Louis Andriessen, George Crumb, Gérard Grisey, and Steve Reich, as well as new works prepared in intense cooperation with Polish composers (22 world premieres in 2014– 17). Improvisation is an important part of their work, as evident on their debut album Visegrad Songs (Requiem Records, Opus Series, 2015). Apart from this project, the group has also improvised to music by Bartók, traditional songs from Warsaw, and works by visual artists such as El Hadji Sy, Laura Lima, and Jenny Holzer. They also appeared in the cycle Photographic Scores with a programme entitled #WITKACY to self-portraits by Stanisław Ignacy Witkiewicz. Their CD #WITKACYwas published in 2018 and its promotional concert took place at the Szczecin Philharmonic as part of the SOUNDLAB cycle. 

Hashtag Ensemble is also involved in artistic education. Since 2016, they have presented a regular cycle of educational contemporary music concerts at the Ujazdowski Castle Centre for Contemporary Art in Warsaw (part of the Smykowizje project). The ensemble performed the works of the finalists at the National Tadeusz Baird Composition Competition at PWM Edition’s Warsaw venue (2017) and the 15th Kazimierz Serocki International Composition Competition at the Polish Radio’s Witold Lutosławski Concert Studio in Warsaw (2017). 

They record for Polish Radio and cooperate with various theatre companies in Poland. They recorded Jan Ekier’s music for Tadeusz Kantor’s 1945 spectacle Death of a Faun, which is the musical component of the exhibition in Cracow’s Cricoteka (May–August 2018). The ensemble’s interpretation of Ignacy Zalewski’s music for the Polish Radio drama after Dante’s Il Paradiso was awarded at the 15th Polish Radio and TV’s Two Theatres Dramatic Art Festival in Sopot (2015), while their performance of Wojciech Błażejczyk’s music for the spectacle Jungle Book was nominated for the Golden Mask (2015). 

The Hashtag Ensemble pays particular attention to the promotion of the achievements of female artists. In 2019, the group will present a programme entitled #MAESTRAS, consisting entirely of works by renowned Polish female composers. At the 2018 Afekt International Contemporary Music Festival in Tallinn, they will perform music by Jagoda Szmytka, Agata Zubel, Agnieszka Stulgińska, Age Veroos, and Rebecca Saunders.