For one, the sounding is caused by the vibration of the strings over an empty box covered by python skin. For two, the 2 strings are controlled without fingerboards. For three, the bow is entwined between the two strings and is never separated from the strings.
Erhu is frequently seen in wuxia books and movies, because it is the poor peasants' instruments and favored by many traveling minstrels. While the typical songs suited for erhu tend to be forlorn, there can be some upbeat songs, too (see below).
The song I chose is called 賽馬 （Horse Race). It is a traditional folk song from, you guess it, Mongolia. It's upbeat, and it features both the bowing and plucking techniques of the erhu. The music conveys very well the vibrancy, the urgency, and the rhythm of a horse race across the open steppes.
I'm including 2 versions of the song. The first is the best version I've found on YouTube, performed by the renowned erhu artist Men Hui-fang. It was accompanied by another traditional Chinese instrument, the butterfly harp. The second version is an updated version by the artist Yang Ying, who is American (emigrant from mainland China). The interview at the beginning gave a bit of introduction to the instrument, as well (though the host made a minor gaffe referring to the Cultural Revolution as the Tiananman Square Massacre). I am not sure that the addition of guitar to the piece was that helpful, but your mileage may vary.
The more traditional version
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The version with guitar