Can an artist/band who has NOT trademarked a stage name sue me if I TM'd said name and use it from here on?

Whether the other bands are popular or not is irrelevant. What is relevant is that they do likely have common law rights in their names, even if their music isn't popular. Rights accrue from use of a mark and if these other bands are still using the marks, they may have rights. As common law rights, they might be limited maybe geographically, maybe even to their particular genre, its hard to say without knowing more. This will also depend on the nature of the marks. A name like GWAR might be more protectable than something purely descriptive like BOB SMITH TRIO or something like that. To fully grasp the situation you might want to talk to counsel.

Trademark rights in the U.S. are obtained by use in commerce. "Popularity" is irrelevant, and you may be sued for infringing common law trademark rights even if the trademark is not registered. You should consult with a trademark lawyer before using the trademark.

The first to use a trademark in commerce in the US has superior rights, even if the mark is not federally registered. Later users of an identical or confusingly similar mark can be sued for infringement. As a practical matter, why use a name that's already taken? Your band should have a name that is as unique as possible.

I agree with the above wise advice, and only add that your situation is a lot more complicated than you might realize. Did you check for any WIPO filings? What were the other potential trademarks that may be an issue—for example, did you clear TMs in music merchandise classes? There are quite a few issues contained within your well-drafted question, and it is a commendable effort to do quite a bit of leg work yourself. However, you may need to at least talk to someone to make sure you don't miss anything. Best of luck!

Q:"Can an artist/band who has NOT trademarked a stage name sue me if I TM'd said name and use it from here on?" A: YES. You are wrong. If they are a band and they perform under a stage name they likely have a "servicemark" (brand name for a service, namely entertainment in the nature of performances by a musical group). In the USA, trademark and servicemark rights arise automatically upon first use in commerce. And, relevant to you, a second comer has a legal duty to avoid likelihood of confusion as to source with the user of any such use-based trademark or servicemark rights. Failure to honor that duty will very likely be trademark infringement or unfair competition. Sounds like that might be your situation. The genre difference is just one factor among many. Since you're in the Ninth Judicial Circuit, you need to review the legal factors, called "Sleekcraft factors" since they arose from a case that compared the use of "Slickcraft" and "Sleekcraft" for recreational boats (and found them likely to result into confusion of source). Google "Sleekcraft factors". Q:"After some google searches I found that there are 3 bands with the same name. 2 are based in the US but are not "popular" (have never signed record deals, can't find an "album" of them, have no social media/marketing sites, not a single song on YouTube, etc.)" A: Contrary to some of my colleagues' answers, that IS relevant to the issue of likelihood of confusion. However, extent of use (popularity) is relevant to whether consumers will be confused by simultaneous use by you of the prior user's band name. If you adopt "The Beatles" for your band name, there is much more likelihood of consumer confusion than if you adopt "Hicktown", even though both are registered. One is probably the most famous band in history, and the other is (to make a pun) just three local bands claiming to be from hick towns. There is (and forever will be) only one "The Beatles", but there might be any number of local hick town bands with the same name without any confusion unless one gets popular, but would they then conflict with "Little Big Town"? Q:"I checked USPTO and there was no active trademarks for artist/bands." A: That's the problem with do-it-yourself lawyering. You do a half-ass job. That is just part of a competent trademark search. You also have to check state trademark registrations and unregistered uses. Any IP attorney doing trademarks knows that. You obviously did not (until now). The only thing you should be doing yourself is finding a lawyer so you don't commit legal malpractice, which so far it sounds like you were doing prior to coming here to . Q:"May I note that my genre and theirs are totally unrelated" A: You may be wrong if you want. Since bands often play many genres, that is pretty much irrelevant. The channels of trade will likely be the same, digital music distribution. Do you really think I can start a country band called "The Rolling Stones", claim I thought of it while skipping stones down by the creek, and not get in deep legal trouble? Do you think I could start my new bluegrass band "The Blues Brothers" or "Blue Man Group" and not get a quick cease and desist demand? Genre might be a factor, but probably a minor one. Note: You are to be commended for checking before proceeding and for realizing there may be danger ahead if you continue on the path you have so far chosen. I hope all of this commendable checking makes you realize you need to retain an IP lawyer so you don't get your band in a melluva legal hess due to false perceptions you have of trademark principles.

I agree with the responses of my colleagues including the detailed response by Attorney Bruce. I think you are way ahead of the game in trying to dot your "i's" and cross your "t's." You will need an entertainment lawyer, regardless, to help increase your bottom line and protect/prevent legal liability. It is smart to start at the inception state, like right now. Best wishes with your matter. Cheers, Uduak Oduok,Esq.