Short answers, pulled from the story.
Jan Vansina defined oral tradition as messages that are oral statements spoken, sung or called out on musical instruments only. He required transmission by word of mouth over at least a generation for it to qualify.
West African griots constituted a hereditary position existing in Dyula, Soninke, Fula, Hausa, Songhai, Wolof, Serer, and Mossi societies among many others. They performed roles including historian, musician, poet, mediator of family and tribal disputes, and spokesperson while often accompanying their telling with instruments like the balafon or kora.
Ancient Indians developed techniques for listening memorization and recitation in schools called Gurukul while maintaining exceptional accuracy across generations. All 1,028 hymns with 10,600 verses of the Rigveda were preserved through specific methods such as Samhita-patha, Pada-patha, and Krama-patha credited to Vedic sages Gargya and Sakalya.
John Miles Foley compiled Oral-Formulaic Theory and Research in New York in 1985 to consolidate oral tradition as an academic field. He founded the Center for Studies in Oral Tradition at the University of Missouri in 1986 and published key works including The Theory of Oral Composition in 1988 and Immanent Art in 1991.
The Quran meaning recitation in Arabic is believed by Muslims to be God's revelation delivered to Muhammad from 610 CE until his death in 632 CE. It was carefully compiled into standardized written form known as Uthman about two decades after the last verse revealed.