taken as T12 “The D will be slightly ช๊าป and the C definitely แฟลต, but at speed the narrowing of the gap between ขั้นคู่ will make them เสียงตรง.” He notes that this system may be “adopted in many places” and also that “A good ครึ่งเสียง [lip] trill also can be made out of a คู่3-4 interval.” A final note from Tuckwell is again extremely practical.