"He's tuning up that old mandolin"

 

Mandolin
Creative Commons Attribution Share AlikeMandolin - Credit: Arent

A mandolin is a smallish, stringed musical instrument related to the lute.  They had developed in Italy by the 17th Century and became popular throughout Europe.  Their size made them extremely portable, so they are often associated with travelling musicians and troupes of actors.  They versatility has meant that they are used in a considerable number of musical styles, for example Celtic Folk and American Bluegrass, as well as early music such as Baroque and Renaissance.  The instrument is thought to have been brought over to North America by Italian immigrants in the 19th Century.