Two songs by Rush - Malignant Narcissism and New World Man.
Malignant Narcissism: Rush was recording their Snakes and Arrows album in the winter of 2007 in the Catskills Mountains of NY. Fender sent Geddy a Jaco Pastorius Signature Fretless Bass prototype for Geddy to play with and share his thoughts. He came up with a bass line so cool, that producer Nick Raskulinecz recorded the bass line through Geddy's vocal mic. (Geddy was finishing up vocals for the album). Nick told Geddy that this needs to be on the album, and for him, Alex, and Neil to come up with a song using the bass line. Neil was still at the studio but sent his drums back to California as he finished up his drum parts for the album. So with Neil using a 4 piece studio drum kit, And Geddy and Alex staying up all night working on their parts, 24 hours later Malignant Narcissism was on the album.
New World Man: Rush producer Terry Brown for the Signals Album wanted to have an equal distribution of music on Side 1 and Side 2 of the Signals cassette. They had 3 minutes and 57 seconds left to fill. So they challenged themselves to write the shortest song Rush had ever recorded to that point (dubbed Project 3:57), and New World Man, their highest Hot 100 Billboard Song ever, was born.
Their shortest song ever recorded? Malignant Narcissism.