On 11 January 2016, Księżyc was a guest on Shells Spent w/ Noble Drew Ali. Księżyc has been played on NTS over 80 times, featured on 72 episodes and was first played on 10 February 2014.

Księżyc (Polish for "Moon") is a folk project from Poland, active in the 1990s, and reactivated in 2010s. Members included Agata Harz (vocals), Katarzyna Smoluk (vocals), Robert Niziński (wind instruments, keyboards), Lechosław Polak (keyboards, lyrics) and Remigiusz Mazur-Hanaj (tapes, lyrics). The musicians themselves defined their music as psychedelic minimalistic folk, with lyrics related to the symbolism of the moon, seen as a symbol of femininity, mystery, transformation and death.

Księżyc was founded in 1990 by three women, Agata Harz, Catherine Smoluk and Olga Nakonieczna (native Ukrainian), and initially was a female a cappella vocal trio, inspired by Slavic folk music from Ukraine, Bulgaria, Poland and Belarus.

The formation changed in 1993: Olga Nakonieczna left, while Robert Niziński, Lechosław Polak and Remigiusz Mazur-Hanaj joined the group. This new line-up recorded the first single, titled "Nów" (New Moon). In autumn 1996 Księżyc released their only full-length album, simply titled "Księżyc". The music, still rooted in Slavic tradition, also brings to mind minimalist composers such as Philip Glass and Wim Mertens. All combined with fairy tales-inspired and surreal lyrics (written by Remigiusz Mazur-Hanaj), the collaboration of Wojcek Czern (Za Siódmą Górą), and the original handmade package.

In 2004 Agata Harz and Remigiusz Mazur-Hanaj created Wędrowiec, a group performing improvised music inspired by Polish folk music.