二弦，亦称广东二弦，系广东音乐特性乐器、古腔粤曲棚面（乐队）和粤乐「硬弓五架头」（二弦、月琴、三弦、竹提琴、直箫或横箫）之头架（领奏乐器）。

「三架头」组合系二弦、竹提琴、月琴或二弦、竹提琴、三弦或二弦、月琴、三弦。

亦有「四架头」（二弦、竹提琴、月琴、三弦或二弦、竹提琴、月琴、直箫或横箫或二弦、竹提琴、三弦、直箫或横箫）组合，二弦都系头架。

现时的五架头是高胡、椰胡、扬琴、秦琴、喉管或直箫或横箫（竹笛）。

琴身、琴筒竹制，蒙蟒皮，张挂2蚕丝弦或钢弦，以硬弓（弓上马尾较紧，相对的软弓马尾较松）拉奏，定纯五度，音色激昂高亢。

The erxian (二弦; pinyin: èrxián; literally "two string") is a Chinese bowed string instrument in the huqin family of instruments. It has two strings and is used primarily in Cantonese music, most often in "hard string" chamber ensembles. In the 1920s, following the development of the gaohu, the erxian experienced a decline and since the late 20th century has been little used outside the tradition of Cantonese opera.