A musical artist named 'Lind Erebros' has a Silmarillion album and two of the songs are titled "Anarkarmeo" and "Isilkarmeo". What could these titles translate to?
Meaning of "Anarkarmeo" & "Isilkarmeo"
It was probably meant to mean "Production of the Sun" and "Production of the Moon"
Anarkarmeo = anar [sun] + carmë [production; making; structure; art of making something] + -o [genitive suffix]
Isilkarmeo = isil [moon] + carmë [production; making; structure; art of making something] + -o [genitive suffix]
Tolkien replaced the ‘k’ with ‘c’ in his later writings and the genitive suffix is not needed in a compound word. So Anarcarmë and Isilcarmë would probably have been better, given that it was meant to mean what I assume.
There is no difference between k and c for the purposes of Quenya. While it is true that Tolkien standardised the c spelling in The Lord of the Rings, in his private notes he used k (perhaps more often than c) throughout his life and long after The Lord of the Rings was published. Some Quenyarists prefer the k spelling for various reasons.
As for the genitive suffix, you are right in that it is not needed in a compound. However I do not think it was attached here because of the compound; rather, I suspect the intended meaning was "Of the making of the Sun" etc. But that, in fact, would likely be an even graver mistake. The English of in this instance comes with the meaning of "about, regarding", rather than implying possession of any sort, and for this function the genitive is wrong one way or another.
@Ellanto What about the Silmarillion and the Atanatárion with omission of Quenta and (presumably) Nyarnar? I suspect those are what the author tried to imitate.
An ellipsis from Quenta Anarkarmeo "Story of the Sun-making"? Possible, of course, and I don't know enough about the author of these titles to judge one way or another. A good possibility to point out though, thank you!