Occasionally when using a third-party application to import a song or other audio content from a CD, that content may be created in a format that will play in iTunes, but will not play properly on an iPhone or iPod touch.
Symptoms may include:

iPhone or iPod touch immediately skips certain songs.
iPhone or iPod touch stops or pauses playback at some point in the song.
The iPod application or Music application quits unexpectedly.

Related posts:

1. iPhone and iPod touch: What to do when applications close unexpectedly while in use
2. What is Gapless Playback?
3. iPhone and iPod touch: Mail may unexpectedly quit if webmail account settings are synced
4. Overview of syncing iPhone or iPod touch with your computer
5. iPhone and iPod touch: Understanding ‘Erase All Content and Settings’