"Happy Xmas (War Is Over)" by John Lennon is one of the most famous Christmas songs of all time. It came out of a cultural context that a lot of younger people probably don't know. During an interview, John explained the meaning of the track. Once you understand "Happy Xmas (War Is Over)," you might not enjoy it as much.

Firstly, some background. Outside of his music, John was probably most known for being an activist against the Vietnam War. His first single without The Beatles was "Give Peace a Chance," a tune that became one of the most famous protest songs against that conflict. To decry American involvement in Vietnam, he paid for a billboard reading "War Is Over If You Want It." The billboard clearly exhorted regular people to bring the war to an end. The billboard's message became a lyric in "War Is Over If You Want It."

During a 1980 interview in the book All We Are Saying: The Last Major Interview with John Lennon and Yoko Ono, the "Power to the People" singer discussed his Christmas carol. "'Happy Xmas' Yoko and I wrote together," he said. "It says, 'War is over if you want it.' It was still that same message -- the idea that we're just as responsible as the man who pushes the button. As long as people imagine that somebody's doing it to them, and that they have no control, then they have no control."

It's interesting that a Vietnam War protest song has become one of the biggest Yuletide songs ever. It's probably so ubiquitous that many people don't bother to listen to its lyrics closely. They probably just get caught up in the song's grand sonic sweep.

The track includes a line where John sings, "So this is Christmas / And what have you done / Another year over / And a new one just begun." John seems to be saying that we all aren't doing enough to end the horrors of war. On some level, he might be correct. Very few of us are out there trying to stop new wars from happening. However, who wants to listen to a Christmas song that guilt trips everyday people for focusing on their own lives instead of political matters that are usually determined by a small group of oligarchs operating behind closed doors? Apparently, a lot of people like this message -- or don't notice it.

On the surface, "Happy Xmas (War Is Over)" was a modest hit on the charts. It reached No. 38 on the Billboard Hot 100 and stayed on the chart for six weeks. The tune appeared on the record Shaved Fish. That compilation climbed to No. 12 on the Billboard 200 and lasted on the chart for 32 weeks.

Judging by its chart placement alone, "Happy Xmas (War Is Over)" was not very successful. However, the song is in heavy rotation every December. Someday, it might be the only song that John wrote to receive any attention.

"Happy Xmas (War Is Over)" has a questionable message -- but it's helped many people get in the holiday spirit.