✔ 最佳答案
Copyright has nothing to do with names. You cannot sue to protect a name using copyright laws.
Trademarks can be protected to prevent others from creating a "likelihood of confusion" about the source or quality of your goods or services in commerce. Social media and social network are not "goods or services in commerce" unless you're helping others somehow (e.g., providing some online access to things or analysis, or other useful services).
The mixtape is copyrighted automatically, but the copyright belongs to the original authors. If you didn't personally compose, perform and record it, then you don't own any of the rights, unless you have a signed document from the original authors (or other chain of title).
"Ideas" cannot be copyrighted. Copyright protects the "original, creative expression", not the ideas, concepts, principles, functions, or discoveries described or shown in the copyrighted work.
Whether you need to register a trademark would depend upon what country you're in. In the USA it is completely optional, but you can register in one or more states or in the federal USPTO, for better rights. Again, it would only apply to a brand being used on goods or services "in commerce". You would look at your state's website (Secretary of State or similar) or the website sourced below.
參考: uspto.gov/trademarks FAQ, Basic Facts, procedures, rules, etc