Metadata is one of the more important aspects of data management, yet many data professionals do not understand or simply ignore metadata management. To clarify this point, consider the metadata that you must manage on your iPod (or whatever device you use) to be able to successfully listen to the music you want to hear when you want to hear it. Without metadata, you’d have a rough time of it!

Why is metadata so important when it comes to listening to digital audio? Well, back in the old days of vinyl and CDs the metadata was printed on the medium and on the case holding the medium. With digital files we’re talking about bits in the ether. Unless they are named reasonably well and tagged with metadata it can be difficult to know just what song is contained in that file.

Accurate and up-to-date metadata makes the digital audio listening experience more enjoyable. What type of metadata? Well, most people, at a bare minimum want to know the song name and probably the artist performing the song. This information – this metadata – makes the music on your device accessible by some means other than random playing. If you make sure that the metadata about the music is accurate when you move it to your device then you can pick and choose the songs you want to play using the device’s interface.

That said, gathering and storing even more metadata for your digital audio files is a good idea. What type of metadata do you need? Think about it before you go about downloading music. As we mentioned earlier, at a bare minimum you’ll want artist and song name. You’ll probably also want to know the album name the song is from, especially if you want to be able to listen to entire albums. And if you’re as meticulous as I am you’ll also want the running order of the album so you can listen to it the way the artist intended: song one, then song two, then…

Probably the next piece of metadata you’ll want is one of the most vexing to get: genre of music. At least it has been troublesome for me. Why? Well, the term is not rigorously defined. Is there a difference between Rock and Hard Rock? What about Hard Rock and Heavy Metal? Do you want to slice genre even finer so that you’d have Thrash Metal, Death Metal, Rap Metal, Hardcore, and maybe even Hair Metal? It might make all the difference in the world to you if you are a metal fan. Or would you classify Led Zeppelin, Judas Priest, Poison, and Slayer all as simply Heavy Metal? Or maybe you don’t care enough about metal music at all, so you’d classify anything even remotely metal-ish simply as Hard Rock… or maybe just Rock.

That is not the only example either. How would you classify Pink Floyd? Rock? Hard rock? Progressive? Some might even classify it as electronic. What about Pop, Power Pop, Bubblegum, and Glam? And then how would you classify Sweet? And would “Little Willy” be classified the same as “Fox On The Run,” or “Love is Like Oxygen,” for that matter?

You really do need to put some thought into the categories you want for genre. If you download all of your songs from online stores like iTunes then the metadata should be set up for you. But it might not agree with what you want. One of the most frustrating things I’ve found is genres like “General Country” and “General Alternative.” Why would anyone want the word “General” in there – making it simply Country or Alternative makes it easier to search later when you are looking for songs by genre.

Perhaps the biggest contributor to collecting all the needed metadata for your digital audio files will be the online music database Gracenote (http://www.gracenote.com/music/). Most digital music software relies on the Gracenote database to automatically populate your musical metadata. If you are connected to the Internet when you pop a CD into your drive to rip the songs, you’ve probably used Gracenote (it used to be called CDDB). Gracenote is incredible because it automatically identifies the CD based on its content (and almost always gets it right). Gracenote automatically populates the artist, album title, song titles, genre, and other metadata fields so you don’t have to. Without this technology a lot of people would have multiple songs out on their hard disks and iPods with titles like Track 1, Track 2, etc. But be careful because Gracenote is not always 100% accurate.

If you are a stickler, like me, Gracenote might at times annoy you (even though you’d never do without it). For example, one of the things I like is consistency. If I am ripping a double disk set (say, something like Hymns to the Silence by Van Morrison) the way I want the title to appear is “Hymns to the Silence (Disc 1)” and “Hymns to the Silence (Disc 2)”. Gracenote will not always be this consistent. Sometimes it will put the parenthetical subtitles in, sometimes it won’t (it depends on the actual album and what is stored for it).

Of course, there are other metadata consistency issues you’ll likely struggle with. How about artist name? Do you want complete accuracy, or should we fudge things to make finding things easier? For example, do you have both Ben Folds and Ben Folds Five, or is everything Ben-related just under Ben Folds? This is probably a poor example because they’d sort right next to each other. How about Paul McCartney? Do we have Paul McCartney, Paul McCartney & Wings, and Wings all based on the actual artist name associated with the disc in question? Or do we just lump all Paul into one of these categories. I want them all under McCartney but that doesn’t mean Gracenote will ensure that consistency – you’ll have to do it.

Which brings us to another significant issue: populating the Sort Artist metadata field. Without this piece of metadata all artists will sort via their first name. And that is probably not what you want. So you have to ensure that the Artist Name is populated (Lou Reed) but also the Sort Artist (Reed, Lou).

Fortunately, you do not have to use Sort Artist for groups, at least using iTunes, because it automatically ignores all of the The’s in the artist names (I wonder what it would do with that 1980’s band The The?) Which brings me to a special case (sort of). Being an 80’s music fan, I have recordings by A Flock of Seagulls and A Certain Ratio. And I always, always sort them under “A” and not “F” or “C”. But that is me. I can understand either way. But you, as a user of your device, have to decide which you want and populate that artist field appropriately.

Other, more esoteric pieces of metadata may be important to you, too. You might want to know the Composer of the song – that is, who wrote it. This comes in handy if you are looking, say, for all Lennon/McCartney songs, even if they aren’t done by The Beatles. Album Artist can come in handy, too. For example, you might have the song “The Saints Are Coming” by U2 and Green Day (Artist), from the Album “18 Singles” by U2. In this case, the artist is U2 and Green Day, but the Album Artist is U2.

But the point of this all is that metadata is required to make data usable by applications. Just try accessing the right data without it!