My list includes some throat singing and various forms of overtone and undertone singing, plus exceptionally high or low voices:
The first time I remember hearing the term “throat singing” was in the 90s when Ondar made some appearances on American TV.
When I was young, quartet singing was big in country music: Statlers, Oaks, etc. All the quartets featured bass singers. JD Sumner is a good example of a gospel quartet deep bass singer.
As far as I’m aware, the first artist to record a Popeye-ish throaty undertone voice was Billy Golden beginning in the 1890s. He’s best known as the first to record “Turkey In The Straw.” Gene Greene did a bit of ragtime “Popeyeing” in 1911, and others followed in the 1920s, eventually getting to the actual Popeye cartoons in the early 1930s.
In 1929, Arthur Miles’ sygyt-like cowboy song is a country music unicorn. He recorded one song in two parts, and that was it.
The White City Jazzers’ throat singing version of “Turkey In The Straw” is from around the same time, but unfortunately, it is not on YouTube. It would be a perfect fit for my list.
Anyway, there’s plenty of obscure, weird-sounding music on this list to enjoy.