Once upon a time, streaming songs across a network from one computer to another was a cumbersome process. Now, thanks to built-in iTunes 4 support for OpenTalk (once called Rendezvous)a networking technology that lets computers find one another effortlessly on a local networkstreaming songs couldn't be easier. Here's how:

1. Launch iTunes 4.

2. Choose Preferences from the iTunes menu on a Macintosh and from the Edit menu in the Windows version of iTunes.

3. Click the Sharing button.

4. In the resulting window, enable the Share My Music check box. Below this check box, you'll see the option to share your entire library or just selected playlists. You'll also see options for naming your shared music and requiring a password to share your music.

5. If you want other users' shared music libraries to be available to you, enable the Look for Shared Music check box.

6. Click OK to close the window.

Now when another computer is connected to your networkeither wired or wirelesslythe music you've chosen to share will be available to that computer within iTunes 4.

If you enabled the Look for Shared Music option in iTunes Preferences, and if that other computer is configured to share its music library, you'll be able to stream its songs to your computer.

To play those songs, simply click the shared-library entry in the Source list and wait for the shared songs to appear in iTunes' main window.

If the password option is enabled on the other computer, you'll be asked for that password. (If you don't know the password, perhaps you're not welcome to share that music library.)

When the songs appear, click the Play button to begin playing the playlist from the beginning, or select a song you want to hear and then click Play.

iTunes is set up in such a way that you can listen to the music from a shared library but not copy it to another computer.

Note that you may not be able to play all the songs in the shared library. For one thing, you can play songs purchased from the iTunes Music Store only if the computer you want to stream the songs to is authorized to play those songs.

If you're a Mac user running an earlier version of iTunes, dread not. Here's a way for you to tune into another Mac's music:

1. Mount a network volume that contains music files that you want to stream to your Mac.

2. If you're using iTunes 3, launch iTunes, and choose Preferences from the iTunes menu. iTunes 2 users will find Preferences in the Edit menu.

3. In iTunes 3, click the Advanced button in the Preferences dialog box, and uncheck the Copy Files to iTunes Music Folder When Adding to Library check box. This option doesn't exist in iTunes 2; that version won't copy files to the music folder.

4. In either iTunes 2 or iTunes 3, choose the Add to Library command from the File menu.

5. In the resulting Add to Library dialog box (called Choose Object in iTunes 2), navigate to the mounted volume and then to a folder full of music files. This folder may be the iTunes Music folder on another Mac, for example. Note that if you're running Mac OS X, you must have sufficient privileges to access this folder. (You'll know you don't if you see a "Do Not Enter" icon slapped atop the networked computer's Music folder.)

6. With the folder highlighted, click Choose. Pointers to the music files within that folder are added to your iTunes Library. To play a song on the remote Mac, simply highlight its name and click iTunes' Play button.

Note: If you try to play a tune from a Mac that isn't mounted, iTunes prompts you to mount the volume.

You can play these files just as you'd play any other song in iTunes. The difference is that they're playing from a remote hard drive rather than from your Mac.

Better yet, because these files are in the Library, the iPod will add them the next time you update the iPodone somewhat-sneaky way to add tunes that aren't located on the Mac that's sanctioned to work with the iPod.