Is It In the Public Domain? Learn How to Tell.

In the US, the public domain is an important part of what is often called the "copyright bargain." Authors (which means all creators, not just writers) are granted a set of exclusive rights for a limited time, in exchange for making their works available to the public. And when that limited time expires their works enter the public domain, where everyone can use them freely.

Here's what the US Constitution has to say:

The Congress shall have the Power ... To promote the Progress of Science and Useful Arts, by securing for limited Times to Authors and Inventors the exclusive Right to their respective Writings and Discoveries. (Article I, section 8, clause 8)

The goal of copyright is to "promote the progress" of knowledge, to encourage creativity and innovation. The public domain is a vital part of this. Creators get exclusive rights for a specific period of time, after which others can build upon those works and use them to make new ones. And really, isn't that the way the creative process works? Romeo and Juliet becomes West Side Story, which in turn inspires West Bank Story.

It's not just works with expired copyrights that inhabit the public domain. A work may also be in the public domain, and free for you to use, because:

• the work wasn't eligible for copyright in the first place; or
• the copyright owner didn't follow certain requirements (back when there were some); or
• the work's creator has dedicated it to the public domain.

Before 1998, the copyright term for works published before 1978 (the date of the current Copyright Act) was 75 years from the date of publication. What that meant was that every year more pre-1978 works would enter the public domain, until they were all there. But then in 1998 Congress decided to freeze the public domain for 20 years.

(If you'd like more information, there's lots more in the tutorial on copyright and the public domain on my Web site.)

The copyright term in the United States is now life plus 70 years. Congress extended the duration of copyright by 20 years (from life plus 50) when it passed the Sonny Bono Copyright Term Extension Act (CTEA) in 1998.

Life plus 70 years is a long time, yes? But it was a disappointment to some. Speaking to a congressional committee prior to the passage of the CTEA, Mary Bono, the widow of musician-turned-congressman Sonny Bono, invoked then-MPAA president Jack Valenti's wish that copyright last for 'forever minus a day':

"Actually, Sonny wanted the term of copyright protection to last forever. I am informed by staff tha such a change would violate the Constitution. . . . As you know, there is also Jack Valenti's proposal for the term to last forever less one day. Perhaps the Committee may look into that next Congress." (CR.144.H9952)

So there's your frozen public domain. Because of the CTEA, no works will enter the public domain until 2019. Who convinced Congress to do this? You know who. Movie studios, corporations, and the heirs of songwriters like George Gershwin.

So what works are in the public domain?

Here's the easy stuff. If the work was published before 1923, it's in the public domain. And if the work was published after 1963, its copyright has not expired.

That's it for easy, I'm afraid. You can't know how long a work's copyright term will last (or if it has already expired) unless you know when (or if) the work was published. A work's publication date will determine whether the current Copyright Act applies, or if the previous one does.

If you want to know whether a specific work is in the public domain, and you have some information about it (like a publication date), you can check a chart, a copyright duration diagram, or this copyright term calculator.

Imagine that you just found a great photograph of Theodore Roosevelt and you want to use it in a book you're writing. Is it in the public domain? You'd think it must be by now, right? But you want to be sure. (You do want to be sure, right?)

Since there's no directory of public domain works to consult, how can you figure out if the photo is in the public domain? Well, to start you'll need to know:

1. When the work was created.
2. When (or if) the work was registered with the US Copyright Office.
3. When the work was first published.
4. Where the work was first published.
5. Whether the work was published with a valid copyright notice.
6. When (or if) the work's copyright was renewed.

How do you gather facts like these? See this copyright and public domain guide for tips.

How do you find downloadable public domain books with Google Book Search? Well, according to Google you simply select the "Full view" radio button when you search on books.google.com. Just enter your terms (for example, horses).

Unfortunately, some searches done this way will bring back results that aren't clear as to which books are public domain (and therefore downloadable). So another way to do it is to limit your search to books that were published before 1923. You'll have to put in a date range, though. I usually use between 1790 and 1923.

What's with Google's "terms" in these public domain books?

First off, I think Google Book Search is a great thing. I really do. I just wish they wouldn't confuse people by adding what look like restrictions.

Google asks that you (among other things):

• Make non-commercial use of the files We designed Google Book Search for use by individuals, and we request that you use these files for personal, non-commercial purposes.
• Maintain attribution The Google "watermark" you see on each file is essential for informing people about this project and helping them find additional materials through Google Book Search. Please do not remove it.

Google has confirmed that those are just requests, they're not legally binding terms. (Source: Search Engine Land)

So no worries. You can use the books however you wish.

If you're looking for public domain sheet music, first a word of caution: there are a lot of sites on the Web that offer sheet music for free, but "free" and "public domain" aren't synonymous.

That said, here's a list of sites where you can find sheet music that truly is in the public domain.

Chopin Early Editions
University of Chicago collection including over 400 first and early printed editions of musical compositions by Frédéric Chopin (1810-1849), all published before 1881. All of the scores in the collection have been digitized.

Christian Classics Ethereal Hymnary
database and indexed archive of public domain tunes for hymns, chants, and carols in electronic formats including MIDI files, printable sheet music, and editable electronic musical scores. It does not include hymn texts or lyrics.

Free Sheet Music Directory: Free-Scores.com
Index to more than 1600 web sites that offer free sheet music. The site also claims to have more than 3000 downloadable public domain pieces (in PDF). Much of the sheet music you'll find through this site is in the public domain, but not all.

The Mutopia Project
More than 700 pieces of sheet music, free to download, print, perform, and distribute. (And the number keeps going up all the time.) Bach, Brahms, Beethoven, Chopin, Mozart, Scott Joplin, and more. You'll also find some modern editions, arrangements, and new music.

Public Domain Music List (PD Info)
Alphabetical reference list of public domain songs, searchable by title. You can also browse alphabetically or by various groupings (Christian Hymns, Christmas Songs, and John Philip Sousa). Some of the sheet music is available in individual reprints or sheet music books for sale though the site.

There's more public domain sheet music on my Web site.