Different iCloud and iTunes accounts on one device

I recently got divorced. My ex-husband has changed the Apple ID password for his account and won't share it with me. All three of my boys are on his account. I can no longer see them on Find My iPhone, or have any access to their texts, web browsing history, etc. As their mother I need that. I want to know if I can create a separate Apple ID for them, use it as their iCloud account, but use my ex-husband's account for their iTunes so they can still have access to all the music, movies, and apps they have accumulated over the years.

Any help anyone can give me would be much appreciated.