I've never been particularly effective at whistling. Some people can't whistle -at all-, I produce a shallow 'blowy/breathy' whistle, which has about 1/4 of an octave range. That article describes the ...

An curved arrow pointing right. Whether it be at a ball game, at a bar, or any other sort of crowded venue, knowing how to do "that whistle" will command everyone's attention. Take control. Produced ...