It was linked to a clip from a musical, Hong Kong Noctune, from the same year, which starred Cheng Pei-Pei. Cheng was at the time also becoming the #1 swordswoman of the wuxia revival, starring in (for example) King Hu's ravishing Come Drink with Me (1966) and Chang Cheh's Golden Swallow (1968).
(For those more familiar with more recent films, she also plays a role as the embittered Jade Fox in Crouching Tiger Hidden Dragon (2000).)
Cheng is the one in the blue dress in the second number, and who sings third in the first. How should we take the words she sings?
Cheng: "Even when your woes are great
Tears are bitter sweet
Everyone has his heart's desire
May all wishes be fulfilled"
chorus: "Hold you head high and strive on
Let no barriers stop your advance
New dancers and singers must arise
Let the world ring with music"
Does this work as a soundtrack to the first video, too?