Harinam is the congregational street chanting of the holy names of God.
Kirtan (Sanskrit: कीर्तन; IAST: Kīrtana) is a Sanskrit word that means "narrating, reciting, telling, describing" of an idea or story. It also refers to a genre of religious performance arts, connoting a musical form of narration or shared recitation, particularly of spiritual or religious ideas.
Source Wikipedia