A band's name can be a trademark or service mark if it is used to sell goods or services (e.g., recordings and/or live performances) under the mark. Accrual of these rights do not require federal registration of the mark in the USPTO. If in fact others were using the mark before you, they might be able to prevent you from using the name as a mark. And if you are aware of such prior use, you are precluded from filing a federal trademark or service mark application to register the mark in your own name. The rule is that the first to use a word, phrase, or design to brand a product or service owns the trademark rights in whatever mark is being used [in this case, a band name] for the same and/or related goods and/or services. No one else may lawfully adopt the same or a confusingly similar mark.