Music is an integral part of Mongolian culture. Among the unique contributions of Mongolia to the world's musical culture are the long songs, overtone singing and morin khuur, the horse-headed fiddle. The music of Mongolia is also rich with varieties related to the various ethnic groups of the country: Oirats, Hotogoid, Tuvans, Darhad, Buryats, Tsaatan, Dariganga, Uzemchins, Barga, Kazakhs and Khalha. Besides the traditional music, Western classical music and ballet flourished during the Mongolian People's Republic. Among the most popular forms of modern music in Mongolia are Western pop and rock genres and the mass songs, which are written by modern authors in a form of folk songs. Traditional music Overtone singing Overtone singing, known as höömij (throat), is a singing technique also found in the general Central Asian area. This type of singing is considered more as a type of instrument. It involves different ways of breathing: producing two distinctively audible pitches at the same time, one being a whistle like sound and the other being a drone bass. The sound is a result of locked breaths in the chest. In Mongolia, the most famous throat-singers include Khalkhas like Gereltsogt and Sundui. Khalkha singers have conceptualized Mongolian lyrical xöömei into several different styles while kharkhiraa remains a separate technique. uyangiin xöömii /melodic or lyrical xöömii uruulyn / labial xöömii tagnain /palatal xöömii xamryn/ nasal xöömii bagaIzuuryn, xooloin / glottal, throat xöömii tseejiin xondiin, xeviiin / chest cavity, stomach xöömii türlegt or xosmoljin xöömii / xöömii combined with long song Long song "Long songs" (Urtyin duu) are one of the main formats of Mongolian music. Firstly, when Genghis Khan first united Mongolia (13th century), many different tribes were brought together, and this allowed sharing of music that had not happened before. The song "Ertnii Saikhan" was a popular song at weddings and imperial meetings, and the song "Oyunt Khuu" was a popular song. The most distinguishing feature is that each syllable of text is extended for a long duration; a four-minute song may only consist of ten words. Other features are a slow tempo, wide intervals and no fixed rhythm. The richer and longer hold a singer has, the more appreciated the singer. Lyrical themes vary depending on context; they can be philosophical, religious, romance, or celebratory, and often use horses as a symbol or theme repeated throughout the song. Eastern Mongols typically use a morin khuur (horse-head fiddle) as