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In Part 1 of this tutorial, I introduced you to Creative Commons, a convenient, no-cost alternative to traditional copyright, but stopped short of implementation and the inherent technobabble.  Here, we'll discuss the first of two steps recommended by the organization for proper implementation of Creative Commons:  file tagging.

Introduction to MP3 Audio Tag FRAMES

Hidden within each MP3 audio file, there exists a bubble of information, a data "tag" containing dozens of descriptive fields, or "metadata," called "tag frames," for such common descriptors as "Song Title," "Artist," and "Musical Genre."  You'll see the values for these displayed in your favorite music software or portable music player.  And with the help of freely-available software applications, these tag frames are easy to add, update and remove from an MP3 audio file.

You might be surprised to learn that the official MP3 audio file format offers no native mechanism for embedding metadata.  Instead, a de facto standard emerged from necessity (and hackers), called "ID3."  Its first version, ID3v1, offers fewer than a dozen of the most obvious audio descriptors and no mention of copyright.  ID3v2, on the other hand, introduced more than 80 pre-defined frame types, including those for copyright and extended copyright information.  As such, when discussing MP3 tagging for the purposes of copyright identification, we must limit our focus to ID3v2 and later versions.

For clarity, pictured below is a diagram of a fictitious MP3 audio file, for a fictitious song recorded by a fictitious band.  [You know the drill.  "Any similarities to persons living or dead...  yada, yada."]

ID3 Copyright Tag Frames

To tag your MP3 audio files for Creative Commons copyright, you'll target three specific ID3 tag frames.  These are:

1. TCOP (Copyright statement) (e.g., "2011, Resort Records Inc.  Some Rights Reserved.  Licensed to the public under http://creativecommons.org/licenses/by-nc/3.0/us/.  Verify at http://rigel7.com/track/everything/download/.")
2. WCOP (Internet URL of Copyright / Legal information page) (e.g., "http://creativecommons.org/licenses/by-nc/3.0/us/")
3. WOAF (Internet URL of official file download page) (e.g., "http://rigel7.com/track/everything/download/")

Unfortunately, your tag editor (discussed next) might not follow standard ID3 tag nomenclature.  If there's no "TCOP" tag displayed, look for "Copyright" or "Copyright statement," for example.  What's more, some tag editors hide these and other, less popular, tags to conserve limited screen real estate.  You'll need to locate and enable an "extended tags" option and/or add the missing tags to the application's customizable tag display.  If no such option exists, you'll need to find a more robust MP3 tag editor.

Tag Editors

Creative Commons offers a free software tool, CC Publisher, for tagging MP3 audio files from a convenient, purpose-built interface.  Unfortunately, I found the Windows version of this program to be prohibitively buggy.  For example, it stripped the album artwork from my audio files.  Furthermore, the app is no longer under development and might never be fixed.  Versions for MacOS and Linux are also offered and may or may not provide better performance.  If you have experience with these, please share in the comments, below.

As Creative Commons gains popularity, expect to find MP3 encoders and MP3 export options native to your professional audio editing software that will duplicate the conveniences suggested by CC Publisher.  Given sufficient demand, there might also arise freeware and shareware applications or online services built specifically for this purpose.  As of this writing, I am aware of none.

Finally, as a last resort, you can tag your MP3 audio files by hand, using any of the popular MP3 tag editors, like the free Mp3tag for Windows, by Florian Heidenreich.  A Google search for "free MP3 tag editors" will turn up dozens of candidates.  Unfortunately, without the guidance of a purpose-built app, this procedure is prone to human error.  Proceed with caution.  Check your work twice.  Here we go....

Manual Tagging, Step-by-Step

Once your MP3 tag editor is installed, follow these steps:

1. With your Internet web browser, select a license from Creative Commons by completing their questionnaire.
2. Select the link:  "See how your license will look."
3. Copy the license URL displayed in your browser's address bar.  It should look similar to one of these:
   • http://creativecommons.org/licenses/by/3.0/us/
   • http://creativecommons.org/licenses/by-sa/3.0/us/
   • http://creativecommons.org/licenses/by-nd/3.0/us/
   • http://creativecommons.org/licenses/by-nc/3.0/us/
   • http://creativecommons.org/licenses/by-nc-sa/3.0/us/
   • http://creativecommons.org/licenses/by-nc-nd/3.0/us/
4. Modify the following copyright statement with your own info, where "2011" represents the audio file's year of publication; "MyBand" represents the audio file's owner; "http://creativecommons.org/licenses/by-nc-nd/3.0/us/" represents the license URL (selected in step #3); and "http://www.mywebsite.com/downloads/mysong/" represents the file's official download page on the owner's (presumably, your band's) web site:
   • 2011, MyBand.  Some Rights Reserved.  Licensed to the public under http://creativecommons.org/licenses/by-nc-nd/3.0/us/.  Verify at http://www.mywebsite.com/downloads/mysong/.
5. In your MP3 tag editor, copy the completed copyright statement from Step #4 and paste into the Copyright tag frame of your MP3 file.  Again, this is technically called the "TCOP" tag frame.
6. In your MP3 tag editor, copy the license URL from Step #3 and paste into the Copyright URL tag frame of your MP3 file.  Again, this is technically called the "WCOP" tag frame.
7. In your MP3 tag editor, paste the file's official download page URL into the File URL tag frame of your MP3 file.  This is the "WOAF" tag frame.  We will discuss the content of your official download page in Part 3 of this article.  For now, you need only know the web page address where this information will be permanently published.

AUTOMATED, COMMAND-LINE TAGGING

Now that you understand the individual steps, there's no reason to repeat them for every MP3 audio file you produce.  With command-line tools, we can apply routine tagging robotically and even to multiple files in one shot.

Perhaps the best and most popular command-line MP3 encoder on the planet is the LAME Project's LAME MP3 encoder.  An open development community, LAME skirts MP3's licensing requirements by offering only uncompiled source code, for "educational" purposes.  To obtain a working build, go to RareWares and download the latest package appropriate for your operating system, whether Windows, Linux or MacOS.  As of this writing, the latest build is LAME 3.98.4.

Once installed, the LAME encoder accepts dozens of parameters.  A typical command-line operation looks like this:

lame mysong.wav mysong.mp3 -b 128 -h --verbose

This example takes the input file, mysong.wav, and generates a 128 kbps bitrate MP3 audio file, mysong.mp3, using a "high-quality" (-h) encoding algorithm.  The --verbose parameter simply provides more feedback, useful for troubleshooting and more entertaining than a blank screen.

Now, assuming that you will always create a 128 kbps bitrate file and employ the same encoding algorithm, we can further simplify this operation by copying the command into a batch program file.  On Windows, this is simply a text file with the .BAT extension.  For example, the following batch file is called encode.bat and contains one command-line statement:

lame %1 %2 -b 128 -h --verbose

Now, we can invoke this batch file with this command:

encode mysong.wav mysong.mp3

...and the result is identical to that of our first example (but with less effort).  In DOS and Windows, any parameters supplied at the command-line are automatically represented in the batch file by variables %1, %2, %3, etc.  We can pass as many parameters as we like and Windows will automatically enumerate them.

Now, assuming that our copyright information won't change much from one song to the next, let's improve our batch operation with Creative Commons' recommended copyright parameters:

lame %1 %2 -b 128 -h --verbose --tv "TCOP=2011, MyBand.  Some Rights Reserved.  Licensed to the public under http://creativecommons.org/licenses/by-nc-nd/3.0/us/.  Verify at http://www.mywebsite.com/downloads/%3/." --tv "WCOP=http://creativecommons.org/licenses/by-nc-nd/3.0/us/" --tv "WOAF=http://www.mywebsite.com/downloads/%3/"

Now, we can invoke the batch file with this command:

encode mysong.wav mysong.mp3 mysong

...and we'll receive an MP3 audio file, mysong.mp3, with the following copyright tag frames and values:

• TCOP:  2011, MyBand.  Some Rights Reserved.  Licensed to the public under http://creativecommons.org/licenses/by-nc-nd/3.0/us/.  Verify at http://www.mywebsite.com/downloads/mysong/.
• WCOP:  http://creativecommons.org/licenses/by-nc-nd/3.0/us/
• WOAF:  http://www.mywebsite.com/downloads/mysong/

Just Tagging

Alternately, if you've already got your MP3 audio file in hand and merely wish to insert the required copyright tag frames, then you can employ the same automation with a dedicated command-line tagging tool, such as Mark Schoolderman's "mass tagger," ID3.exe.  [If you re-tag your MP3 audio file with LAME, the audio will be unnecessarily re-encoded, degrading quality.]

For example, this batch program - I've saved it as retag.bat - performs the same copyright tagging operations as above, but on an MP3 audio file, using the aforementioned ID3.exe command-line tagger:

mp3 -2 -wTCOP "2011, MyBand.  Some Rights Reserved.  Licensed to the public under http://creativecommons.org/licenses/by-nc-nd/3.0/us/.  Verify at http://www.mywebsite.com/downloads/%2/." -wWCOP "http://creativecommons.org/licenses/by-nc-nd/3.0/us/" -wWOAF "http://www.mywebsite.com/downloads/%2/" %1

The batch program file is invoked with this command:

retag mysong.mp3 mysong

Note that there are only two parameters in this batch program file.  In this case, the specified MP3 audio file, mysong.mp3, is overwritten with the updated file.

Needless to say, you can take this batch automation to all sorts of extremes, creating command-line parameters for the band name, year of copyright, encoding bitrate and more.  And for all of those other things that don't change from song to song, you can embed many of them automatically into every MP3 audio file you produce, with ID3 tag frames like WOAR (official artist/performer web page), WCOM (commercial information web page), and WPUB (publisher's official web page).  Again, there are over 80 pre-defined tag frames to consider and new tag frames being added with each new ID3 revision.

Double-check Your Work

This warning deserves stern repeating:  Before sharing your MP3 audio file with anyone, be sure to verify the content of its TCOP, WCOP and WOAF ID3 tag frames in a dedicated tagging application, like the aforementioned Mp3tag.  To that end, know your tagging app and, particularly, how it presents the TCOP, WCOP and WOAF fields.

Once you release your MP3 audio file into the wild, there's no "take backs."  While you might be able to replace those uploaded to music sharing sites and social networks with updated versions, there's no guarantee that your original, flawed tracks won't tour the Internet forever.

Moving On

Now that we've identified where the example audio file's official download and verification page will be located, http://www.mywebsite.com/downloads/mysong/, we must create that page and add it to our website.  In Part 3 of this article, we will discuss this second and final step of the Creative Commons licensing process, beginning with an introduction to Universal Resource Names (URNs) and the Base32-encoded SHA1 hash algorithm.

Don't quit on me now, Ringo.  We're almost there.