addition to the Sundanese forms of Gamelan in Parahyangan, the region of Cirebon retains its own distinct musical traditions. Amongst Cirebons' varying Gamelan ensembles the two most frequently heard are Gamelan Pelog (a non-equidistant heptatonic tuning system) and Gamelan Prawa (a semi-equidistant pentatonic tuning system). Gamelan Pelog is traditionally reserved for Tayuban, Wayang Cepak, and listening and dance music of the Kratons in Cirebon, while Gamelan Prawa is traditionally reserved for Wayang Purwa. Cirebon also retains specialised Gamelan ensembles including Sekaten, which is played in the Kratons to mark important times in the Islamic calendar, Denggung, also a Kraton ensemble, which is believed to have some "supernatural powers", and Renteng, an ensemble found in both Cirebon and Parahyangan known for its loud and energetic playing style. Zither ensembles Tembang Sunda is a genre of Sundanese vocal music accompanied by a core ensemble of two Kacapi (zither) and a Suling (bamboo flute). The music and poetry of tembang Sunda are closely associated with the Parahyangan, the highland plateau that transverses the central and southern parts of Sunda. The natural environment of Priangan, an agricultural region surrounded by mountains and volcanoes, is reflected in some songs of the tembang Sunda. Kacapi suling is tembang Sunda minus vocal. Tarawangsa is a genuine popular art is performed on ensemble consists of tarawangsa (a violin with an end pin) and the jentreng (a kind of seven-stringed zither). It is accompanied by a secret dance called Jentreng. The dance is a part of a ritual celebrating the goddess of paddy Dewi Sri. Its ceremonial significance is associated with a ritual of thanksgiving associated with the rice harvest. Tarawangsa can also be played for healing or even purely for entertainment. Bamboo ensembles The three main types of Sundanese bamboo ensembles are angklung, calung, karinding and arumba. The exact features of each ensemble vary according to context, related instruments, and relative popularity. Angklung is a generic term for sets of tuned, shaken bamboo rattles. Angklung consists of a frame upon which hang several different lengths of hollow bamboo. Angklungs are played like handbells, with each instrument played to a different note. Angklung rattles are played in interlocking patterns, usually with only one or two instruments played per person. The ensemble is used in Sundanese processions, sometimes with trance or acrobatics. Performed at life-cycle rituals and feasts (hajat), angklung is believed to maintain balance and harmony in the village.