This is actually pretty cool, even if I'm blind I somehow happen to know by the harmonics how drone reeds vibrate. What is happening is, whenever you strike up, the first (buzzy) tone you hear is the fact that the tongues are more open than closed (I.e., tapping staccato on the tongue beds). Then they click over into their usual tone when playing the chanter (more closed than open, I.e. legato strokes on the bed). The harmonics will change depending on whether the tongues are tapping staccato or legato, but a lot of pipemakers don't realize that the true harmonics of a set of drones (played with the chanter) are actually created via the legato strokes, not the staccato strokes (these staccato harmonics are also heard when popping a finger out of the drone without the bag pressurized). Hopefully this makes some more sense. Each time the tongue hits the bed on each legato stroke, the bottom of the stock, tuning chambers, top bores, etc all act like a bell and rings at its own frequency.
This is actually pretty cool, even if I'm blind I somehow happen to know by the harmonics how drone reeds vibrate. What is happening is, whenever you strike up, the first (buzzy) tone you hear is the fact that the tongues are more open than closed (I.e., tapping staccato on the tongue beds). Then they click over into their usual tone when playing the chanter (more closed than open, I.e. legato strokes on the bed). The harmonics will change depending on whether the tongues are tapping staccato or legato, but a lot of pipemakers don't realize that the true harmonics of a set of drones (played with the chanter) are actually created via the legato strokes, not the staccato strokes (these staccato harmonics are also heard when popping a finger out of the drone without the bag pressurized). Hopefully this makes some more sense. Each time the tongue hits the bed on each legato stroke, the bottom of the stock, tuning chambers, top bores, etc all act like a bell and rings at its own frequency.