64kbps AAC+?
Pandora told me they encode their music to 64kbps AAC+, and it sounds great, but I'm not sure how to get that in iTunes. I have mp3's but Pandora's sound just as good and their format would take up less space. How do I get their format?
I assume you mean how can you import your music into iTunes at 64Kbps AAC, or how can you convert your existing music into 64Kbps?
It can be done, but before you do, have you listened to the Pandora feed on good speakers? It may sound very different. If you use a Bit Rate of 64Kbps for your music now, you may then be disappointed with the quality of the sound if or when you upgrade to higher quality. 64Kbps is probably acceptable for speech, but I'm not so sure about music. (Actually, definitely not for music.) The usually lowest accepted Bit Rate for music is 128Kbps. (See my additional comment, below about your current choice.)
To import from CD at 64Kbps, click on Edit/Preferences/General>Import Settings. Set Import Using: to "AAC Encoder" and then select the Setting: "Custom". This will cause another dialogue box to appear. In this dialogue box, set Stereo Bit Rate: to "64Kbps" and click OK. (Leave the other boxes as they appear.)
I strongly advise you to test a few songs at this point. Import some songs that you already have in iTunes at the higher bit rate. Use your best quality speakers, stereo, Dock or headphones (in fact, try all your different types of listening device) and listen to both versions of some of your songs. If you are happy with 64Kbps, that's fine. But frankly, I'll be surprised if you are. (Your choice of course!)
However, since one of your other posts mentions that you have your music in WAV form, I will be very shocked if you don't notice the difference in quality between WAV and 64Kbps! 😮, I say!!
For songs already in your Library, such as previously imported CDs, or MP3s that you've purchased, now that you have changed the Import Settings to 64Kbps AAC, all you need to do is highlight a song and select Advanced/Create AAC Version and iTunes will create a copy of the song, but at a bit rate of 64Kbps. This will take a long time for all your songs. Perhaps ed2345's suggested software (in another of your posts) can bulk convert, can it?
Then, if you use Sync and Sync only ticked songs and videos to manage your iPod, un-tick the high Bit Rate songs and leave the new versions ticked "on". Then at the next Sync, this will remove the high Bit Rate songs and put the lower quality ones on instead.
If you are unsure what format a particular song is in, highlight it and look on File/Get Info/Summary>Kind and also the ../../>Bit Rate.