That people with any rate would hardly have songs in your library, or do not like music, you can skip songs come when I do not feel that I have. Such, but most do not wish to listen to music synchronized to the iPod can be configured to ignore it in iTunes.
This is Internet radio "Pandora" for "hearing a month (don't play for a month)" function is very similar.
Basically, the song skips several times over, it is determined that the tracks do not like iTunes, smart playlists us off from a specific month. When you are creating a Smart Playlist from the drop-down menu "skipped the last day," choose a certain time period (one month for example) is OK if you specify. This makes it ignore the playlist a song that was skipped in the past month.
Also like the above image, the number of skips "less than three times" and if you add another filter, skip one or two songs will be synced to your playlist. This song has been deemed not live in the songs just do not like skipping just one.
To rate a song with all the more so that the work put into playlists, less than one star, I think in a much more comfortable this way. And if the iPod's capacity is low, very useful to filter a song about hearing. Please try us.