How to prevent iTunes from deleting music on my iPhone

Question

I know this is a very basic question but I haven't ffigured it out for my old iPod, let alone my newly acquired iPhone 4s.
I have a large amount of music, obtained by digitising high quality FM broadcasts which I want to transfer to my iPhone 4s (as I previously did with a non-Apple smartphone). But my experience of using my old iPod is that every time I synced the iPod with my PC using iTunes the process began by deleting all the music I had there. Although this was extremely annoying, I found no way to stop iTunes doing this.
I have now browsed internet artices on how to transfer my recorded music to my iPhone. There appears to be no other route than using iTunes, and, yes, it confirms that syncing will delete any music I have on the iPhone. Although I currently don't have any, the next time I do this it will delete my music collection. In effect this means that I have to keep a cumulative snapshot of what is on my iPhone to make sure I load all that was on there previous to the 'current' syncing.
I though that computers were designed to make things easier - but this is just adding a lot of work. Is there less user-antagonistic software than iTunes that I could use to make the job of regualrly adding music to my iPhone simple ? (btw I rarely need to add 'songs', only music, but I find references only to the process of adding 'songs' - what about other types of vocal music, such as opera, oratorios, a capella, choral etc ?).

Answer 1

No, iTunes is perfectly capable of adding or removing one or two tracks from an existing selection of 2Gb or so and only adding or removing the changes. As long as you haven't changed the rest of the library around, which is what I thought you were driving at...
For moving a library between machines see this migrate iTunes library post. iTunes gives each track a unique ID, which is how it maintains playlists, syncs stats even if you edit metadata in the meantime. What gives it a headache if you create a new library and reimport the content as each track in the "new" library has a different ID from the one it had in the old one. The earlier link is for associating an iPod/iOS device with a new library with minimal loss of data, but if you've rebuilt the library you still have to go through the process of reloading the media. If you migrate the library properly it is as if nothing has changed.
tt2