The first shell, Terebra Turritella, contains the ability to release 12 notes or an octave and a half of the diatonic musical scale of notes. A straight line of five finger pitch holes, drilled into whorls 2, 3, 4, 6 and 8, will release these notes. This shell sounds like the cooing of Mourning Dove and will attract these birds.
This shell’s common name is the Screw Shell because it looks like a large brownish colored wood screw. The colors can vary from chestnut brown to beige. It grows in many marine environments around the world and varies in length from an inch to seven inches long. Larger specimens are found in the tropics. I call this instrument the Screw Shell Flute.
The next shell, Rysotta Ovum, also contains the ability to release the diatonic and pentatonic musical scale of notes. Finger pitch holes are drilled into the shell’s whorls following X/Y coordinate lines centered on the shell’s spiral apex or beginning. The notes are deeper sounding than the notes produced by the Screw Shell Flute.
The common name for this shell is either the Muffin Shell or Cinnamon Bun Shell because that’s what it looks like. I call this instrument the Muffin Shell Hoot. They really do sound similar to large owl calls. I make them with two finger pitch holes.
I’ve examined and tested many shells during the ten years I have been researching this phenomenon and found only two shell species that release musical scales of notes. Only one contains the ability to release enough chromatic, diatonic and pentatonic musical notes to play most tunes and songs. That is the Screw Shell Flute.
Screw Shell Flutes are available in the keys of B, C#, C, D#, D, and E. The length of a Screw Shell determines what key it is in. Once I select shells in these keys I drill and smooth the finger pitch holes, shape the mouth holes and finish the instruments with mineral oil.
I recommend Screw Shell Flutes in the key of B for men with big hands, the key of D for women with average size hands, the key of E for children (10 and older) with small hands (smaller than an average size woman’s hand) and the key of C for men with average size hands and women with a bit longer fingers and thumbs than average. I don’t recommend the Screw Shell Flute for children younger than ten.