itunes Music Tags

When i sync my songs to ipad for the first time i realized that some of them has tags - which i hate- Because you cannot sort songs with their file names (just names but not file names options) songs with unwanted song title tag and which doesnt are not together
For example:
Marlene Dietrich - Vie En rose has a Vie en Rose song title tag
Marlene Dietrich - Lili Marleen has no info in it.

When itunes sorts songs one is in Marlene Dietrich M section the other one is in Vie en Rose V section.

So i decided to erase all tags in my computer and then tell itunes that there is no tags with those songs anymore. But there is NOT a REFRESH method as far as i can see.

Do i have to erase all them and Sync again? Or what to tell itunes on my Vaio that the tags have been changed hellooo!

Yet again i am not sure whether i could do that this time ipad itself would not see the changes.. Sigh...