No, it is not “Stairway To Heaven”, although that is a “long song” which is TBH longer than most “typical” songs. It also is not from the pop, rock, metal, or hip hop genres. The longest song ever recorded does not come from a present day performer per se like Lady Gaga, Post Malone, or Billie Eilish.
Through 2019, the Guiness World Records notes that the longest song ever recorded came in at a whopping 13 hours, 23 minutes, and 32 seconds. The name of the song is “The Rise And Fall Of Bossanova” and the artist is PC III.
SMH, as we know Tool is known for lengthy tracks and of course the use of time signature in music, as displayed in tracks like “Parabola” and “Vicarious” among others not to mention references to dogma. But, hey they can’t touch a track that is over 13 hours long!
The longest “pop” song ever recorded is titled “Apparente Liberta”. The 76 minutes and 44 seconds long marathon is by Giancarlo Ferrari.
Not sure how to determine accurately the longest song ever played on the radio, but with the YOLO nature of society now hooked on GIF and MEME and Tiktok and Twitter we have doubts few if any would pay attention long enough to listen to it in its entirety.