Co-founder of Požoň Sentimental ensemble (1994). The works he recently composed include the opera "66 Seasons" (stage premiere 2013, Košice), the melodrama "Apolloopera" about bombing of the Apollo refinery in 1944 in Pressburg (premiere 2013), many pieces for chamber ensembles, choirs, music for film (eg. Stones, Cooking History, Mimi&Lisa;, Four, Last Folio...) and theatre. He is co-founder of Middle-Class Chamber Orchestra Požoň Sentimental and collaborated with ensembles Musica falsa et ficta, Mio-Mio, Piaček-Pavelka-Michalec, Brass Band Štós, Voise Over Noise, Audiobratia, Pink Big Pig, [email protected], POVAŽAN, Frutti di Mare, Tuleň, VENI ensemble, VENI Academy, VAPORI del CUORE, Son-Drian, Upokojenci. Piaček’s music was featured at Warsaw Autumn (i. e. commissioned work “Happy Mainstream”), Wien Modern, Wiener Festwochen, Melos-Ethos, Evenings of New Music, Musica Danubiana Ljubljana, Bratislava Music Festival, KioSK festival Žilina, Fest Anča Žilina, 4 živly Banská Štiavnica, Festival of Nice Music Banská Štiavnica, New-New Festival Brno, New Slovak Music festival, Exposition of New Music Brno, on many concerts at home and abroad. He performed improvised music with musicians like Nick Collins, David Dramm, Hilary Jeffrey, Ann LaBerge, Beth Griffith, Jean-Marc Montera, Günter Müller, Chris Newmann, John Oswald, Otomo Yoshihide, Jon Rose, Miki Skuta, Daan Vandevalle, Marián Varga, Elliot Sharp, Alfred Zimmerlin, Hankil Ryu, Petr Vrba...