I think (without reading all of the previous posts) that we also need to be clear on what a ‘dead name’ is and is not, as well as how it does and does not apply to an artist name.
For example, using this specific case -
This person put out music under artist names of Eric Taxxon, Patricia Taxxon, and Tedrich Lendum.
This person, if I understand correctly, claims that Eric Taxxon was never their legal name.
So, if it isn’t a legal name, why isn’t it an artist name the same as Tedrich Lendum?
Do we change Tedrich Lendum because it is a ‘dead name’?
And if Tedrich isn’t a dead name - why not?
I can see if, as example, an accountant named John Smith becomes Jane Smith and becomes a musician - I can understand why the name John Smith doesn’t apply to MB and is easily considered a dead name, as there was no music released while living as John Smith.
But that is not what we have here. Here we have a person named X (using X because we don’t know a legal name), who put out music using 2 artist names (Eric and Tedrich), and then became Y (using Y because we don’t the the new legal name) and created a 3rd artist name that ‘replaced’ at least one of the artist names.
So, what is a dead name?