You are asking a lot of questions, and providing zero information from which the answers to any of the questions might be determined.
These are complex questions, because usually the band members don't enter into written agreements which would have made them simple questions.
All you can do is go to an experienced attorney like myself, explain the facts as best you can, provide whatever documents there are, and start working with the attorney to try to take an assertive position.
Don't expect answers to questions. We are lawyers, not magicians, and have no power to solve the mysteries which you yourself created.
As my colleague has stated, you are asking a lot of questions but providing little information . Absent an agreement, you and the other band members might be considered co-authors of the intellectual property under law. I suggest that you consult with an entertainment attorney.
The best answer to your question is 'maybe.' That's all any lawyer can tell you without actually sitting down with you and looking over everything that has happened in your specific situation and then doing some legal research.
You need to meet with an experienced music attorney in your area ASAP.
I would also suggest that you immediately purchase and read attorney Richard Stim's book on Music Law (see link below). It will make your attorney meeting more efficient if you have a better understanding of the issues ahead of time.
Any answer or other information posted above is general in nature and is not intended, nor should it be construed, as legal advice. This posting does not create an attorney-client relationship between you and the posting attorney, and you are urged to engage a qualified attorney who is licensed to practice in the relevant jurisdiction.
Here you had only an oral band partnership (and you probably neglected to even discuss these things among yourselves, but nonetheless, that's how it works) so it's your band's partnership, not any individual partner, that owns the band's assets, including the band's name/trademark, recordings, album artwork, and social media accounts.
Since you didn't treat this like the business it's supposed to be before, you now have to see a lawyer to help straighten this out, and to get your paperwork in order for the future. CONTRACTS prevent problems. Get some.
Avvo doesn't pay us for these responses, and I'm not your lawyer just because I answer this question or respond to any follow-up comments. If you want to hire me, please contact me. Otherwise, please don't expect a further response. We need an actual written agreement to form an attorney-client relationship. I'm only licensed in CA and you shouldn't rely on this answer, since each state has different laws, each situation is fact specific, and it's impossible to evaluate a legal problem without a comprehensive consultation and review of all the facts and documents at issue.
As my colleagues point out, failing to properly set up your band in the first place leaves you in a messy situation now. You will need to see an attorney for answers to these questions.
The author is a Maryland attorney; however no answer given on Avvo is intended as legal advice or intended to create an attorney-client relationship. Dan's expertise lies in the electronic entertainment (video game) industry, as well as complex internet law issues, electronic free speech, entertainment law, copyright and trademark law, and computer fraud. He primarily represents game developers and founders of emergent internet technologies.