You're listening to a favorite song in iTunes and want to hear other tracks that replicate the mood. At the click of a button, Apple generates a playlist of songs that mix well together.
Those are the smarts behind the addictive Genius playlist and music-recommendation feature Apple launched last week as part of iTunes 8 software. It's a little like Pandora Internet radio, except you don't have to be online.
Music-recommendation tools are taking center stage. I've also been testing rival approaches unveiled Tuesday as part of Microsoft's Zune software update.
I've been trying out Genius on my iTunes library of 5,800 tracks and on new iPod Nano and Touch devices Apple also unveiled a week ago. Despite a few lapses, Genius has a high IQ.
When I clicked the Genius button while listening to James Brown's It's a Man's Man's Man's World, iTunes created an instant playlist with Marvin Gaye's Mercy Mercy Me (The Ecology), Al Green's I'm Still in Love With You and Jill Scott's A Long Walk, among others.
Another playlist based on the Three Tenors' (Luciano Pavarotti, Jose Carreras, Placido Domingo) classic Nessun Dorma included Maria Callas' rendition of Un Bel Di, Vedremo from Madama Butterfly.
Not every match was obvious: Does Bobby Darin's Mack the Knife really go with Hall & Oates' Maneater?
Apple says it goes well beyond genre in generating the playlists. The company anonymously sends information about your library to the iTunes Store and combines that with data from other users to fine-tune playlists and buying recommendations. Suggestions show up in a Genius sidebar in iTunes.
You can create (and save) playlists of 25, 50, 75 or 100 songs and click "refresh" to generate an alternative list. Depending on the "seed song," some tunes turned up on the original Genius playlist as well as on subsequent refreshed lists based on the same song.
You can generate playlists in your library only with songs that are among the 8.5 million for sale at iTunes, ruling out The Beatles' songs in my collection. Apple says as Genius gathers more information, it will work with artists missing from the catalog. Some classical tunes also failed to generate playlists.
And while the Genius sidebar is supposed to recommend songs you're missing from an artist you've selected, as well as tracks from other artists, iTunes flubbed some buying recommendations. When I played a few Van Morrison tunes, the sidebar suggested "missing" songs from Denise Morrison and Darren Morrison instead of Van.
USA TODAY columnist Edward C. Baig reviews tech products, trends and services each week.
READERS: Have you used music suggestion features? What are the best and worst songs or bands you've learned about through these services?