Symphony No.9 in E minor Opus 95 (2) Antonin Dvorak
No big deal, just whistling the most difficult aria ever written...
It's one of the world's most virtuosic and challenging coloratura arias, but Mozart's moment from The Magic Flute is no match for American professional whistler Michael Barimo.
Barimo has a pursed-lips range of more over three octaves, with all the agility needed for Mozart's ornaments and fancy flourishes (technical term).
It definitely went down a treat with the audience. Apparently the video was filmed at a party at violin virtuoso Joshua Bell's residence. That's some party-piece.
*writes off rest of day to practise whistling*