iTunes sync does not delete songs My wife's iPhone 4 has some albums synced on her iPhone that are not selected to be synced in iTunes.

She has "Selected playlists, artists, albums and genres" selected.

She is using a wired sync and Wireless Sync is disabled.

/edit
All her content in iTunes, and that synced to the iPhone, is ripped from the original CD.
/endedit


No playlist contains this album
the artist is not selected
the album is not selected
no genres are ticked at all


How is the album still there after sync?

Please note, I told her about the ability to remove the album from within Music on the iPhone, this question is purely about why the album is still there after a sync with iTunes.

/edit
All her content in iTunes, and that synced to the iPhone, is ripped from the original CD.  She is not using iTunes Match.
/endedit
"Sync only checked songs and videos" was un-ticked.

When an iOS device is connected to iTunes, under the device's Summary tab, the Options section has a checkbox Named "Sync only checked songs and videos"; this option enforces the removal of music that is not set to sync if it has been synced to the device in the past.

Ticking the box and then syncing removed the offending album.