I'm writing a song but the title is already in another song. Can I still use the title?
Well, no one can sue you. Some people have already said this, but no one can license the name of a song, so you're free to name your song whatever you'd like. Be careful about using very distinctive phrases for your title, though. If you're going with a generic word or phrase (for example, "Yes"), no one's going to call you out for using the same song title as someone else (I have at least three songs in my iTunes called "Yes"). But some songs coin really distinctive phrases, and I'd recommend avoiding these (for example, "Don't let the sun go down on me" isn't the sort of phrase you should just drop into a song). If you use a really memorable line from another song as your title (another example, "Bohemian Rhapsody"), people are either going to see it as a reference to the original song, or plagiarism.If you're dead set on using a really familiar title, though, no one can actually do anything about that. Just be prepared for people to expect the original song and compare yours to it when you play it for them (if you told me you were playing a song called "Bohemian Rhapsody", and it's not the original, I'd be a little disappointed). Ultimately, you can't get in trouble over song titles, so you really do whatever you like. Now, if the actual song is similar another song, you can be sued for that.
Is it legal to write a book based on another book, movie or play?
I want to write a different version of Swan Lake, this version will be very different and the characters will have different personalities, it will also end in a way which i don't think has been done before. I fairly sure it is legal as things like fanfic exist with no repercussions, but i was wondering if there are any details i need to add in so as not to get in trouble, like mentioning it's based on Swan Lake at the beginning or something?
Can two books have the same title?
Yes. It is possible (and quite common) for two or more books to share the same title. It is best to avoid this situation unless you are positive that there won't be any confusion between the two titles. (Perhaps one title is very old and out of print; or the the two books are on radically different topics.) If the two books are on the same topic and are both in print at the same time, confusion may occur, leading to frustration for everyone involved in the book publishing process, including the potential book buyer.The only time when it is not possible to re-use the title of an existing book is if that title contains a trademark. Note: It becomes possible to register a trademark related to a series of books once two or more of the books in that series have been published. For example, I was able to register the trademark THE MOTHER OF ALL for the various books in my pregnancy and parenting series once first two titles, The Mother of All Pregnancy Books and The Mother of All Baby Books, had been published. I could not have attempted to trademark the books if I had only written a single title.See related document at US Patent and Trademark Office:http://www.uspto.gov/trademarks/...