Tachum
C Doublings to Low A, and B Doublings to Low G with E Gracenote as used in Strathspey playing (Round movement)
In orchestral music the Tachum is known as the Scotch Snap
Being able to play The Tachum (half doubling) is a requirement for SCQF Level 3
Being able to play The Tachum as a Doubling with E Gracenote (Strathspey movement) is a requirement for SCQF Level 4