Better ears than mine are needed, but in the recording by Brian Miller of blue whale z-calls that is embedded in this BBC story, the drop each time seems to be not far off a fifth - or perhaps slightly flat, closer to a tritone? https://twitter.com/casparhenderson/status/1329492805270573061">https://twitter.com/casparhen...

“Do human voices sound as ethereal to the whale as whale voices sound to us? Or do we scratch and irritate the whale, a pin in the ear?” @rebeccagiggs

Unhinged Monday morning thought: what if the blue whale mentioned in the first tweet in this thread is part of a long term musical conversation working its way through subtle gradations of dissonance and harmony? Cf humans & tritones from ~23 minutes here https://www.bbc.co.uk/sounds/play/b08t15sq">https://www.bbc.co.uk/sounds/pl...