Which one is the pop and which one is the rock from Hey Jude and Born This Way?
My vote goes to Hey Jude.
Generally pop is recorded in a different fashion being the instrumentation different, too.
Rock is a little more organic, using mostly instruments, and pop being more digital using samples, therefore while The Beatles are considered pop by a part of the public, their compositions, including Hey Jude, are more instrumented and less electronic and sampled than songs full within the pop genre like Born This Way.
Hey Jude slayed Born This Way, it seems like the controversy about similarities took much of the possible unanimous positive acclaim it could have got.
Nevertheless, Hey Jude's melody is regarded as one of the most memorable of modern music history, for me the ending is just epic and pretty much justifies The Beatles craze. In my opinion both songs are great but I would, too give an edge to Jude because of that ecstatic and difficult to achieve celebratory moment in modern music that is the ending.
An anthem for the new generation, 'We Found Love' put EDM into serious levels when it smashed everywhere in the world. Its appeal not only impacted in the pop world, the not before expressed in such explicit way realities of real struggle in love and drug addiction and the divorce from other unrealistic love pop videos put Rihanna on a different level than her peers later replicated by them.
The song also changed songwriting in pop music as its structure is repeated in later pop hits. The video is widely acclaimed and won VMA for Video of The Year and is currently nominated for a Grammy for Best Video in Short Form.
It slayed the world.
Versus
Nirvana - Smells Like Teen Spirit
Nirvana catapulted itself to glory with 'Smells Like Teen Spirit'. Regarded by a lot from the public as one of the best songs of all time, the strength of this song not only made Nirvana famous, it changed an entire young generation.
'Smells Like Teen Spirit' shows how great of a songwriter Kurt Cobain was, melodically he turned his emotional melodies with a great dynamic into an anthem, Butch Vig knew how to work with Kurt's great talent to produce a song that most rock fans unanimously respect. It not only hit everywhere and help sell its parent album Nevermind over 30 million copies, it became the last rock hit that brought a whole new rock population to the charts.
After Smells Like Teen Spirit, rock hits became slowly more and more a rarity in charts dominated by other genres like pop, R&B, hip hop and dance.