Another exciting sound often played on the harmonica is the trill. A trill is a rapid alternation between two inhaled notes or two exhaled notes. This can be achieved either by rapidly moving the harmonica from side to side while maintaining a steady breath, or by rolling the head from side to side while holding the harmonica steady.
Both these methods are common in harmonica playing. A trill is indicated by two holes (eg. I ) with the symbol Y written above them.
When you begin learning the trill, you may have trouble getting the notes to sound clearly and evenly. Here is an exercise which should help. Take it slowly at first.
Here is a typical Blues lick using the trill on holes 4 and 5.
Here is a variation. The rhythm is exactly the same as the previous example, but the notes have been changed. The trill here is between holes 3 and 4.