That's not a salad, it's a symphony

Vendors at the local market in Beijing could be forgiven for thinking that Nan Weidong and Nan Weiping run a restaurant. But the bags stuffed full of vegetables the brothers lug back home are used for a very different purpose -- musical instruments. The two grew up surrounded by vegetables in China's central Anhui province, but their music teacher father encouraged them to learn conventional instruments from a young age. As teenagers, they joined a local theatrical troupe.
But it wasn't until two years ago that they thought of making instruments out of vegetables, an idea that has fascinated them ever since.
They now live and work in a narrow Beijing apartment, drilling holes in carrots, marrows, lotus roots and Chinese yams and testing the pitch against an old electronic tuner -- nibbling silently on the shavings all the while.
A sweet potato becomes a perky ocarina, a bamboo shoot a mellow, reedy flute. A row of carrots tied upright to leeks is transformed into a set of Chinese panpipes.
"The deeper the hole, the lower the pitch. The shallower the hole, the higher the pitch," said pony-tailed Nan Weiping, at age 41 the younger by two years.
"The size of the holes also matters to guarantee the quality of the sound. The leeks only serve as decoration."
But controlling the pitch is extremely difficult, he added, with changes in the air temperature and humidity potentially warping the shape of the holes, putting the notes out of tune.
Their repertoire is as varied as their instruments, ranging from traditional Chinese flute music to Western songs such as Auld Lang Syne.
The two have appeared on numerous talent shows in China and often receive payments of 30,000 to 50,000 yuan ($4,800 to $7,900) for a performance -- their sole income. Each show requires making a whole new set of instruments.
Though the size and shape of the vegetables is important, the utmost importance is placed on freshness, said Nan Weidong.
"If the water content in vegetables evaporates, the tune will become higher than the basic tune, or even out of tune. Therefore we choose vegetables with as much water content as possible," he said.
"The vegetables have to be solid and hard. We can't use vegetables left over for days. They are too soft to be played."