手风琴是一件附有键盘的自由簧乐器。演奏时，中央部份需要左右伸缩，以引入气流颤动琴内的簧片发声。

1822年由德国人布希曼（Friedrich Ludwig Buschmann）创制；1829年经奥地利人岱密安（Cyrill Demian）等改良而渐趋完善。

现代手风琴有键盘式手风琴（钢琴式手风琴）和键钮式手风琴（钮扣式手风琴、巴扬手风琴）两种，中国及中西欧主要使用钢琴式手风琴，而俄罗斯、爱尔兰主要使用巴扬手风琴。钢琴式手风琴比较容易掌握，常作为学习钢琴的基础，可以演奏各种古典或现代音乐；巴扬手风琴音域广，由于键钮小，手移动速度快，可以演奏许多高速度高难度乐曲，总体以演奏俄罗斯，爱尔兰民乐为主。

Accordions (from 19th-century German Akkordeon, from Akkord—"musical chord, concord of sounds") are a family of box-shaped musical instruments of the bellows-driven free-reed aerophone type, colloquially referred to as a squeezebox. A person who plays the accordion is called an accordionist. The concertina and bandoneón are related; the harmonium and American reed organ are in the same family.