Since the 1950s, the Israel Defense Forces (IDF) has run performing groups called "Lehakot Tsva'iyot" (Army Ensembles). These groups, comprising enlisted soldiers with talent or performing experience, tour bases and field positions to entertain the troops. Performing original materials meticulously prepared and performed, these groups became leaders in the Israeli music and entertainment field. Many of Israel's most popular songs were written for the Lehakot Tsva'iyot – for example, "Dina Barzilai" (words: Haim Hefer, music: Sasha Argov), "Halleluya" (words and music: Yair Rosenblum), "Yeshnan Banot" (words: Yoram Tahar-Lev, music: Yair Rosenblum). Dubi Zeltzer, considered one of the founding fathers of Israeli pop music, wrote many of the songs for the Nahal Brigade entertainment troupe.