Now that I'm tuneless, I've realized two things...

My hard drive cable popped off as I left work one day. That sucked. Despite routinely hearing songs in my head, in rich, monophonic reproduction(*), I can't imagine doing it for any length of time.

(* I seem to have a good memory for music, as long as there's no music playing that I can hear, but I have no ability to manage the spatial separation in my head, so it's all in mono. Very bizarre.)