One day in the late 1970s, Rush member Alex Lifeson flew his bandmates, Geddy Lee and Neil Peart, into Toronto International Airport. The airport's IATA identification code of "YYZ", broadcast by the airport's VHF omnidirectional range system as Morse code, greeted the music crew as they approached. The repeating rhythm called like a siren... inspiring the band to write a piece to exploit the sequence.
(Y) - . - - (Y) - . - - (Z) - - . .
I love this instrumental piece.
(The video embedded above I shared from the super Canadian band's YouTube channel.)