[Chiharo]

^ The word can be used as to "describe the best work of a particular artist" only if it's used that way. Just saying that it's a masterpiece generally just means that: "one of the best albums made ever." The word "masterpiece" shouldn't be used so lightly, especially not by artists when describing their own albums, at least in my opinion. But anyway, I'll still see it the way you wrote it.

Edit: Ironically I think this is her worst album. Which doesn't say much because I really love all of her albums. Though I'd put LOVELAND last on my list of favorites.