The Irish concertinas is a diatonic keyboard concertinas, using free reeds, excited by a variable wind
provided by the bellows operated by the musician. It designates the different variants of two-tone concerytinas
organized according to one or more diatonic scales (unlike the chromatic concertinas),
although there are diatonic concertinas that are not bi-sonic like the Russian diatonic accordion, the garmon.
If some concertinas models have all the notes of the chromatic scale
(such as some continental three-row models or Irish concertinas),
they retain an organization by diatonic scales.