I've recently been creating my own rendition of Amazing Grace, and while I was working to add a bit of stylistic elements to it, I imagined a melody in my head which would require 3 beats in the space of one eighth note.
I am aware that this sort of thing exists, as I have often heard it, but I have not managed to find either the name of this note, or how it is written.
To add a bit more clarity, I am looking for three equal beats in the space of one eighth beat. Here is an image of what said note might look like (at least how I imagined)