why won't the music I just added sync with my ipod

It depends on how your iPod nano is currently set up to sync. Manually or automatically. If you don't know, select the iPod in iTunes, so that you see the iPod's settings screen in iTunes window. Along left side, in the sidebar, under Settings, click Summary (probably already selected). To the right, you see the main device settings for your iPod. Find the checkbox for Manually manage music [and videos]. If that box is checked, the iPod is set to use the manual method to load content. If it is not checked, you are using automatic syncing.

Manual seems more likely in this case... On the horizontal bar that goes across iTunes window, click Music button (at left end) to show your music library. Near middle of bar, click Playlists. A sidebar appears along left side of window, with your iPod listed under Devices. In the main part of window, you can change the view of your music library using the control at right end of horizontal bar. I usually use Songs, to show a plain list. But in this case, Albums may work better. In any case, drag the songs you want on the iPod from the music library to the iPod in the sidebar. You can probably drag the whole album (CD) with Albums view. You can select more than one item at a time when you do this. Alternately, instead of dragging to iPod, you can right click on selection and Add to Playlist -> [your iPod name].

If your current iPod setting is for automatic syncing, please post back.

Automatic syncing does not necessarily mean everything you add to your iTunes library is added to your iPod. It depends on how you set it up. You can set it up to sync "everything," but only if your iPod's storage capacity can hold your entire music library. (When you select iPod in iTunes, the "capacity bar" at the bottom of iTunes window shows how much storage space on iPod is being used.) Or you can set it up to sync a portion of your iTunes library, such as selected playlists you create in iTunes.

If you want to use automatic syncing, go to the iPod's Music setting screen in iTunes. To see this screen, select iPod as you did earlier, to see its Summary settings screen. Then, in the sidebar, under Settings, click Music. To the right, you see the iPod's Music settings screen.

NOTE: If you change to automatic syncing now, iTunes replaces iPod's current content based on how you set up this Music settings screen. iTunes is not adding to what is there now, it is replacing. Any songs on iPod that are not in your iTunes library (on the computer) will be lost. If all of your songs are in your iTunes library, no problem.

At the top, there is a checkbox for Sync Music. If your iPod is set for manual loading, it should not be checked. Checking that box turns ON automatic syncing. You can try this (to see how it is set up) and click Revert at the bottom to set it back to the manual setting. Below that, if your music library can fit on your iPod, you can select the option to sync Entire music library. Otherwise, select the option to sync Selected playlists, artists, albums, and genres. Below that, there are four lists for selecting what iTunes syncs to iPod. In this case, you could select the 6 new albums under Albums. However, the more convenient way to set it up (for ongoing use) is to create (one or more) playlists in your iTunes library (or use existing playlists), and add ALL songs you want on your iPod to those playlists. Then, on this screen, under Playlists, select only those playlists. In this case, if you have it set to automatically sync your "iPod playlists," you would add those 6 new albums to one or more of those playlists in iTunes. Your iPod does not need to be connected when you do this. The next time you connect the iPod (or click Sync if already connected), iTunes makes the same changes to the iPod (adds those 6 albums).

NOTE: If a song is on more than one playlists synced to iPod, iTunes only adds one copy of song file to iPod.

One benefit of using this method is if you ever need to do a Restore on the iPod (erases iPod), or you buy a new iPod. You can simply set up this screen again to sync those same playlists, and your iPod is like it was before with just a few mouse clicks (and a short wait for syncing). If you use the manual method, it may take hours to re-load what was on the iPod (assuming you can remember).

If you want to continue using manual loading, click Revert at the bottom. If you want to set up automatic syncing, set up this screen as desired and click Apply at the bottom.