Here are two mid-1960s recordings of traditional music from the album Music of Laos, recorded by Alain Daniélou for the UNESCO Collection series and reissued by Rounder Records in 1999. The first is "Love Song" sung by Miss Sai Thong with Thao Phet accompanying her on khène.

Next is "Melodies for Two Khènes" played by Thao Vong and Thao Som. According to the liner notes, tradition allowed musicians to improvise their melodies.

Here's a photo from the CD's notes of an unnamed man in Vientiane playing a khène.

I came across an article that questioned the veracity of the CD's notes, and lamented that the Rounder reissue hadn't corrected them. When I googled the singer's name, Miss Sai Thong, trying to learn more about her, I found links only to towns and resorts in Thailand that have that name, which made me wonder if it was some private joke about her looks.

go to link, listen the song: