A decision must be made on an official national anthem for Scotland following confusion caused by the Commonwealth Games, according to campaigners.
Winning Scots athletes have heard Scotland the Brave
While Flower of Scotland is regularly played at football and rugby grounds, athletes have instead celebrated medals down under with Scotland the Brave.
SNP MSP Michael Matheson said it was time to "sort out" the confusion and define Scotland's national song.
He said he had raised the issue at the Scottish Parliament.
"We must be one of the few nations in the world without a specified anthem", he said.
"We have a situation where different sporting bodies are using different tunes.
"The SFA and the SRU both use Flower of Scotland and the Commonwealth Association have decided, for some reason, to use an old song of Scotland the Brave."
Mr Matheson, culture spokesman for the Scottish National Party, said the matter needed to be addressed before the 2014 games, which Glasgow is bidding to host.
He said: "Should Glasgow be successful, when the band strikes up the national anthem the crowd could fall silent - very few people actually know the words to Scotland the Brave."
Hamish Husband, of the Tartan Army, said the changing songs confused other nations as well.
He told BBC Scotland: "I remember being behind the Iron Curtain in East Germany where we respected their anthem.
"When Scotland the Brave came on, a couple of thousand kilties did the Highland fling.
"That certainly did confuse the authorities and the fans in that country."
He added: "My personal choice would be to have Auld Lang Syne."
Anthem campaigner Roddy Martine would like to see something new.
He said: "I would love for a Scottish composer to come up with something completely different.
"Scotland the Brave is always going to be an iconic song, Flower of Scotland has the political connotations with Edward II and references to Bannockburn, while Highland Cathedral was written by two Germans.
"We need something fresh and new for a new Scotland."