Dear Dear Rich: I'm making a documentary about my aunt who's a well-known accordion player and there is a scene in which people sing 'Happy Birthday' to her and she joins in on accordion. Someone told me that I need to get permission to use that song in the film. Is that true? Can that really be true? The answer depends on who you ask. If you ask Summy-Birchard, the publisher that earns about $5,000 a day from the song ($2 million a year), the answer would be "Yes." If you asked Law Professor Robert Brauneis, the answer would be a definite "No." It seems like the world's most recognized song has benefited from a checkered copyright history. It's possible the whole song is public domain, or that just the melody (written in 1893) is PD. But considering the vested financial interests in protecting the copyright -- nobody has ever litigated the issue -- you probably can't afford to challenge the song's owner. We wish we could hear your aunt's accordion version but we're glad that the squeezebox birthday spirit lives on somewhere!