Q: If a song in my iPod is on multiple playlists does it use up more memory or space for each time in a playlist in my iPod? Also, how can I get as many MP3 songs as possible or extra songs on my 4GB iPod nano?
– Lorenzo

A: The content on your iPod is organized using a database which “points” to the actual MP3 files on your device, rather than storing MP3 files in a folder structure by playlist. This means that each MP3 file is only stored on your iPod once, regardless of how many playlists it is contained in.
To get more content on your iPod nano you will want to look at the bit-rate that your songs are currently encoded at.
The amount of space that an MP3 file takes up is based entirely on the bit-rate of that file, and Apple’s estimate for how many tracks you can store on an iPod is based on 128kbps MP3 or AAC files. If your files use a higher bit-rate, they will be larger and you will therefore be able to store fewer of them on your device. There is, however, a tradeoff between sound quality and bit-rate—most users do not consider anything below 128kbps to be acceptable CD quality audio, and some would suggest that even this bit-rate is too low.
You can check out our Online iPod Storage Calculator to see how many songs you can fit on your iPod based on different bit-rates. To determine the bit-rate of an individual song in your library, simply select the track, choose File, Get Info and look at the “Summary” tab. You can also add a bit-rate column to your track listings in iTunes by going to the View Options on the View menu and selecting the “Bit Rate” option.