Ha Mai Ven comes from Po Nghieu village, Thuy Hung commune, Cao Loc district, Lang Son province. According to her, different sub-groups of the Nung people possess different genres of Sli. The Nung Giang people have Sli Giang, the Nung Chao have Sli Sinh Lang and Co Lau and the Nung Phan Slinh have Sli Phan Slinh. Each melody is presented in the form of singing with Sli words.

Sli songs tell us about nature, the moon and stars, trees, mountains, and hills. Historical and social events are also told through Sli songs. People greet each other by singing Sli. Particularly, the Nung people often sing Sli on their Lunar New Year and during other festivals. The Nung people also sing Sli for birthday and wedding parties. 

During birthday parties, they sing, “Many happy returns of the day. Today is a good day. Your children are dutiful and your family is prosperous.”

Sli Sinh Lang of the Nung Chao people is sung in repartee between a male and a female group.

Ven loved singing Sli when she was small, often participating in village art movements. In 1999, Ven won Prize A from a folksong festival for ethnic minority groups in Lang Son province. Her performance was selected to join the province’s singing contest and eventually won a gold medal.

Since then, Ven has been often invited to sing Sli in big festivals and cultural events within and outside the province. She joined an autumn art and cultural exchange festival in Guangxi, China, in 2000.

Ven works tirelessly to preserve and develop Sli songs to make them more interesting. She has written many new songs in praise of the Party, president Ho Chi Minh, changes in her native land and efforts to prevent HIV/AIDS.

Ven also introduces the content of the song in the Viet language before singing to audiences that include people from different ethnic groups. 

She says that bamboo flute accompaniment will make Sli singing sweeter and traditional costumes and jewelry will help to make singers look more attractive. 

Ven is currently a member of the folksong preservation association of Lang Son province. She still participates in Sli performances, teaches Sli singing, and acts as a member of the jury board for Sli singing contests. She spends Saturdays and Sundays training her children in playing the Tinh traditional guitar and singing Sli and other traditional melodies.