There is a Cantonese song! I heard it at McDonald's a couple days ago and thought it was so good I recorded it, but how do I find it? The tune is very similar to "Drifting Snow

Gao Shengmei's "Butterfly Butterfly Flying All Over the Sky" is the Mandarin version of Vivian Chen's "Puffing Snow". If you say the tune is very similar to "Drifting Snow", then it means it's sung by Vivienne Chan. Although Vivienne Chan doesn't sing anymore, she has a lot of classic Cantonese songs. Like "A Thousand Que Songs", "A Promise Gone By", "Where Do We Meet in Life", "Night Machine", "Foolish Girl", "Dancing Street" and so on. The conditions you gave are not sufficient to judge which one it is, but you can search out and listen to each of these classic Cantonese songs of Vivienne Chan that I recommended, and you will know which one it is.