Having trouble understanding sampling rates for my music library

[mayhem117]

Today I just discovered that my itunes has been encoding all my music with a 48kHz sample rate. After some research online I've come to the conclusion that the sample rates should really be set at 44.1 kHz. My question is can I take all my music and convert it (within itunes) back down to a 44.1 kHz and still restore it to where it really should be without it negatively affecting the music quality? or would it be better to get it from the source again?

 

[I. G.]

I think it's not a good idea to resample back and forth between 44.1 and 48kHz...

 

[John]

Depends on the source. Are you sure the source is not sampled at 48, eg some DVD tracks? If the source was cd then I am with I.G. You really need to re-rip them. They will never be right if you just re-sample.