By Allan Hoffman,c.2006 Newhouse News Service

For all the convenience of digital music and iPods, something is missing – the liner notes and album art previously packaged with recordings.

Just mention this to anyone who grew up during the heyday of LPs and you will likely jump-start a nostalgia-fest, if not a rant about the sterile nature of digital tunes. The absence of cover art, photographs and liner notes seems like a genuine loss to generations accustomed to physical records and CDs.

You connected to an artist through the songs, of course, but also through the packaging of the album itself.

Until now, record companies and online music stores haven’t offered much in the way of a substitute. If you buy albums at the iTunes Music Store or other online music stores, you typically get nothing more than an image of the album cover. If you’re lucky, you may get a digital image of the CD’s booklet.

But that is likely to change, as record companies begin to realize more people might buy digital music, rather than burn their CDs (or trade MP3 files online), if they were packaged with something akin to liner notes for digital music players and personal computers.

The work of a New York-based startup, TuneBooks, hints at what we are likely to see emerge as a substitute for the materials packaged with CDs. TuneBooks produces “interactive digital liner notes,” called TuneBooks, combining lyrics, photos and artwork, as well as links to downloads of ring- tones and posters.

When you buy an album, the TuneBook is downloaded along with the songs.

So far only two TuneBooks are available at the iTunes Music Store (for albums by the Click Five and the Darkness), but Josh Koppel, co-founder of TuneBooks, said the company is in talks with record labels to produce many more – even to produce them for entire back catalogs of music. That would mean you might be able to buy albums from the 1960s or 1970s at an online music store and have the original artwork and liner notes, along with extras.

“This is an idea that’s now in the brains of the labels,” Koppel says. “Right now, we’re very much at the infancy of this whole idea.”

Think of next-generation liner notes as being something like the bonus features packaged with DVD releases. You will have the tunes from the album, but you might also get video interviews, promotional posters and previously unreleased photos.

You might even get fun interactive games to play on your PC or iPod.

With such features, music lovers may even be willing to buy music they already own – certainly an incentive for record companies to move forward with plans to package album art and other ephemera with their digital music. You may already have “Greetings From Asbury Park” on your iPod, having burned the CD you bought 10 years ago, but if you can get a version with a video clip, the original liner notes and other extras, you may buy the digital-only release.

Today’s generation of music fans, of course, will expect as much. An album won’t be an album without the digital extras.