The concertina is a small free-reed instrument with bellows, similar the accordion. It is played by pushing and pulling the two ends of the instrument between the hands while pressing melody studs on either side with the fingers to select the notes. When the player opens and closes the bellows, pressure is created inside the instrument. Pressing a particular stud will allow a reed to vibrate as air is pushed past it due to the pressure inside, which is what produces the sound.
The concertina comes in various sizes, with ranges spanning from one to four octaves. The concertina is typically hexagonal in shape but rectangular versions also exist. The concertina differs from the accordion in that it doesn’t have a keyboard, and while on the accordion the each stud will create a chord, on a concertina the studs will typically only create a single note.
The concertina is said to have been invented by Charles Wheatstone, in 1829 and the first to play it at a public concert was Giulio Regondi, who in the mid 19th century toured Europe as concertina player. He also wrote 2 concertos and other shorter pieces for the concertina.