Children and parents across Japan are singing a tango song with the refrain "dango, dango" (rice dumpling). Entitled "Dango Sankyodai" (Three Dumpling Brothers), the song has simple but amusing lyrics and is accompanied by an accordion and piano. It has also become one of the best-selling songs ever. The tune first appeared as part of an NHK (Japan Broadcasting Corporation) children's program called Oka-san to Issho (Together With Mother). Though it was originally scheduled to be aired for just one month, the station received so many inquiries about the song that two months later, on March 3, it was released as a CD single--rare for a children's song. Dango are a traditional Japanese sweet made by kneading rice flour with water and shaping the mixture into little balls, which are then steamed. Often they are put on a skewer three or four at a time, coated with soy sauce, and then roasted. Or they can also be topped with a jam made of red beans. Dango are traditionally offered during festivals, such as for tsukimi (moon viewing) and hanami (cherry blossom viewing), but are also commonly eaten as a snack. In the song, the three dumplings on the skewer are brothers--each with a distinct personality. Though they sometimes fight over differences in the way they've been roasted, they are very close, hoping that the next time they are born they will be together again on the same skewer, dipped in plenty of bean jam. Why has this song become such a big hit? Many reasons have been given: the lyrics are fun and easy to remember; the words dango and tango are pronounced almost identically in Japanese but conjure up such different images; their hand-drawn cartoon image is cute; or that Japanese simply love dango. But the real secret might be found in the phrase sankyodai (three brothers). People have pointed out that because fewer children are being born in Japan, families with three siblings have become rare. As a result, many children who hear the song wish they had more siblings. Over the last 30 years three children's songs besides "Dango Sankyodai" have become big hits. Another tango tune, "Kuro Neko no Tango" (Black Cat Tango), sold 2.2 million copies in 1969. In 1975 a song featuring another Japanese sweet that is shaped like a fish and filled with bean paste entitled "Oyoge Taiyaki-kun" (Swim On, Mr. Taiyaki) sold an amazing 4.5 million copies, the most ever for any Japanese single. And the theme song for the cartoon series Chibimaruko-chan called "Odoru Ponpokorin" sold 1.6 million copies in 1990. "Dango Sankyodai" has already sold over 2.6 million copies and is well on its way to becoming a classic children's song. Photo: The cover of the CD single, with the oldest brother at the top, the youngest at the bottom.