Links
Here are some links that you may find
useful and interesting:
www.sarahhopkins.com
http://www.australianmusiccentre.com.au/artist/hopkins-sarah
www.exo.net/~pauld
Specifically, HERE you will find
an article on the physics of whirlies.
https://mortonmusic.com/archives/composer/hopkins (Sarah's Choral Music publishers)
email: sarah@sarahhopkins.com
Click here for the Sarah Hopkins website.
( Visionary Music & Inspiring Performances )