> You can make a derivative work as much as you want to, you just can't redistribute it.
Well, no one is likely to know if you don't redistribute it, but legally, no, you may not:
17 USC § 106: “Subject to sections 107 through 122, the owner of copyright under this title has the exclusive rights to do and to authorize any of the following: [...] (2) to prepare derivative works based upon the copyrighted work;”
This does seem to be the correct interpretation. The consequence is that even reading a book aloud at home would be a violation of copyright. However, that would likely be defensible in court as fair use, if it came to that.
Well, no one is likely to know if you don't redistribute it, but legally, no, you may not:
17 USC § 106: “Subject to sections 107 through 122, the owner of copyright under this title has the exclusive rights to do and to authorize any of the following: [...] (2) to prepare derivative works based upon the copyrighted work;”