On this fourth of July, you might hear the Star Spangled Banner being played.
Or some un-official national anthems, like God Bless America or Stars and Stripes Forever.
Almost every country has an Official and Unofficial anthem.
Today we kick off an occasional series on the Unofficial ones.
We go to Spain, where people not only disagree on the lyrics to their Official anthem.
They can't agree on what the Unofficial anthem should be.
The World's Gerry Hadden reports.
This is the Spanish National anthem, and as we've reported before, it has no lyrics, because Spaniards can't agree on what they should be. This is a nation with strong regional identities and differences. So, identifying an 'unofficial' song that speaks to the Spanish experience, is difficult.
Spaniards everywhere know this 1971 hit, Mediterraneo, the singer, Joan Manuel Serrat, from Barcelona, is known as the Bob Dylan of Spain.
He sings, "perhaps because my childhood self still plays on your beaches, perhaps because my first love still sleeps hidden in your canefields, I carry your light and your scent with me wherever I go. On your sands I've stored my love, my adventures, my suffering. I was born on the Mediterranean."
Serrat's song is a Spanish classic, but people from Spain's Atlantic coast or from the interior probably wouldn't pick it as their national song. For example, Spanish singer, Ana Belen, embraces central Spain. The Madrid born star made this song, about life under dictator Francisco Franco, famous:
The lyrics say, "Spain, white shirt of my hopes, from outside or in, sweet or bitter. Whoever put this restlessness in our gut set us free but clipped our wings. He took our bread and left us only hunger, Spain, you're a dove searching for starrier skies where we can all understand each other without destroying each other."
For some, like Barcelona pre-school teacher Mari Pujol, 'Camisa Blanca' transcends regional differences.
Mari says 'Camisa Blanca' is the song that unites Spain more than any other. "I'm a Catalan nationalist and I don't feel that I belong to Spain," she says, "but if I had to choose, this song is the best because it speaks to Spain of Franco, of our Civil War. Of the hunger. It is very explicit. Luckily the Spain of today is different."
But Spain's conservative say, this is all liberal gibberish. Many Spaniards still see Franco as a hero that saved Spain from communism. They're part of a traditional crowd, who will always stand up and dance a "Paso Doble," to this classic, Paquito el Chocolatero.
According to Spain's Society of Authors and Editors, Paquito el Chocolatero was the most played song in live performances last year. The 1937 diddy is a staple at weddings, communions and town festivals.
But with no concensus about a national song, some Spaniards resort to humor to decide the issue, and say this should be the country's unofficial anthem:
This is Manolo Escobar's 1960s camp hit I'm modern, but Spanish. It says, "Gentlemen, I'm an man of the 20th Century, but Spanish. I can laugh about anything, except God. I like to hear the bells of my church, and I like to sing and to protest when something is not right. So don't come around and try to buy my pride. I know how to lose, goes the chorus, better than I know how to win."
Mr Furia of the popular Spanish band, The Pinker Tones, says this song expresses Spain's confusion about it's identity during the 1960s.
Mr Furia: "In the 60s Spain still considered itself like the last religious and cultural bastion of Christianity in Europe. Because everyone else was going mad. You know, the hippies and drugs and free sex. Being Catholic was the real thing. And being very with the state and with a conservative attitude toward life - that was supposed to be a good Spaniard. In the official 1960s."
But Mr. Furia says the country is much different today, undergoing rapid changes. Thanks to a wave of immigrants from around the world, 21st century Spain is more diverse than ever. So if it's been historically difficult to find a song that captures what it means to be Spanish, its even tougher today.
For The World I'm Gerry Hadden in Barcelona.