As an unhappy decade nears an end, here’s my nominee for the Top Ten list of loveliest songs of the 2000s: “Wishful Thinking” by the Ditty Bops. Here’s the original, in the witty, captivating video version. And here’s an a cappella rendition of it by amateurs; between the bathroom acoustics and the young women’s marvelous harmonies, it, too, is a treat.