Sailor Diatonic Harmonica Series in Tremolo tuning fitted with plastic comb.
What do we mean by Tremolo ? Diatonic Harmonicas in Tremolo tuning have a divided comb. This makes it possible to blow (or draw of course) two reeds at a time while one reed is tuned a little bit higher than the corresponding note in the upper channel. This causes a bright and smooth sounding tone -
The 'Tremolo'. Sailor 48
Diatonic Tremolo Harmonica with 2 x 24 holes
Popular music often uses improvisation that contains a maximum of 3 chord type: Tonic Dominant and Subdominant chords. Many pieces accommodate only two chords (Tonic and Dominant chords). With the diatonic tone layout a lot of popular melodies are playable.