Away, Come Bye, Walk Up, Come Here and Lie Down, traced from Michael Moura's whistle commands video (Moura Stock Dogs). Each graph shows the pitch (frequency) over time, measured from the video's audio. Play sounds a synthesised copy, Slow plays it at about half speed, and Original opens the video at that command.
Whistle into your microphone and watch the frequency you're hitting. The sound is analysed in your browser; nothing is recorded or sent anywhere.
Captured automatically when you pause, and lined up against a command.