TremoloTremolo-tuned harmonicas are mainly used for folk music. They are easily recognisable by the horizontal division of the air channels. Each channel has two reeds for each note, one pair for blown notes and another pair for drawn ones.
These reeds – which are basically identical – are tuned to slightly different frequencies. When played together, this difference causes the characteristic beating of the tremolo sound, a guarantee for a cheerful and merry tone!