What is the longest song lengthwise (actual playing runtime) ever to top the Billboard Top100 music chart?

"American Pie" released in 1972 by Don McLean is the longest song lengthwise (actual playing runtime) that has ever reached number one on the Billboard Hot 100. American Pie ran 8 minutes, 36 seconds. Although technically the song was created in two parts (parts I & II), both parts were played together creating the one song. In second place is "Hey Jude" released in 1968 by the Beatles at 7 minutes, 11 seconds. Of interest is the shortest song ever to reach number one on the Billboard Hot 100 which is "I'm Henry VIII, I Am" by Herman's Hermits at 1 minute 49 seconds.

On the week ending November 12, 1955, Billboard published The Hot 100 for the first time. Their 50th anniversary was in 2015 and is still the standard by which a song's popularity is measured in the United States. The Hot 100 is ranked by radio airplay audience impressions as measured by Nielsen BDS, sales data compiled by Nielsen Soundscan (both at retail and digitally) and streaming activity provided by online music sources.