If you look up Don McLean in Wikipedia, it says that "McLean declined to say anything definitive about the lyrics until 1978. Since then [he] has stated that the lyrics were also somewhat autobiographical and present an abstract stoy of his life from the mid-1950's until the time he wrote the song in the late 1960s." The common belief has been that it refers to the event whereof Buddy Holly, Ritchie Valens and Big Bopper went down in a plane crash on February 3, 1959.
Waylon Jennings could have done a song about that fateful plane flight, for he had
personal involvement. He gave his seat up to Richardson (Bib Bopper) because
Jennings had a cold that day, and didn't want to fly. If he had not turned his
seat over to Richardson, Jennings wouldn't be here to sing anything these days.
But Jennings has more class than that. He had to leave the subject to someone
else. That's not something he could have sung about, IMHO.