Whistle Challenge

A conversation on twitter has led to a challenge. Talk amongst twitter friends about them being unable to use a shepherds whistle I found myself saying that it really couldn't be so difficult. A few days later this shiny red whistle arrived in the post. The challenge is to master the shepherds whistle.
Now I love a challenge but this one leaves me light headed & dribbling! The family say I'm driving them mad & the dogs don't know if they're coming or going!!
However, I can now give a rendition of Happy Birthday & am working on commands to use with the dogs. It is far more difficult than I imagined & the trick is to make the same sound more than once!
I won't be defeated, though I could be in danger of being thrown out of the house!!