Looking to find a specific sci-fi romance book. I remember major plot details, but not titles, author, or character names.
I'm looking for a book series (I think it's either three or four books) about aliens coming to Earth. The alien race is human-like and human-presenting, but they're abnormally tall and have supernatural strength and intelligence. The female main character is in her upper teens (like 17-19 or something) and has a younger teen brother. She lives with her parents and her dad takes care of the family. Her mom is sick and dying and she used to be a famous opera singer, or a famous singer of some sort. Earth is dying and the aliens come to save the top athletic and smartest teenager humans to come back to their planet. The female lead is not the most athletic, but then she sings and it turns out that she is a rare human that posesses the ability to create the alien frequencies for their technology, which is rare in the alien race and only royalty possess the ability. She uses this to make one of their ships fly, which catches the aliens' attention. Her brother passes the athletic test, and the aliens decide to let her join as well because of her voice. From what I remember, humans aren't supposed to be able to make the frequencies. On the journey to the alien planet, the female lead falls in love with the alien prince. I believe there are some slightly spicy scenes between them, but I'm not 100% sure. When the ships arrive back on the alien planet, the female lead meets the alien king and he is not impressed with her and won't let the prince marry her unless she becomes a full citizen of their planet. The only way for her to do that is to compete in another competition against other non-citizens. It's high stakes, because many people train for years for it and still end up dying from it. She enters the competition and wins, which grants her full citizen status. She then requests that her parents also be brought back to the planet. However, she finds out that her mom died and is mad that she didn't get to say goodbye. The aliens still bring her father back, and she ends up getting married to the alien prince. At the wedding, per the alien customs, she isn't supposed to dance with or touch any other man for the first year of marriage, but her new husband knows how much it means to her to have a last dance with her father and grants her permission to do so.
As far as I can remember, the first book covers the competition on Earth, the second covers the journey back to the alien planet, and the third covers the other competition and wedding. And before you suggest it's The Chronicles of the Invaders series (Conquest, Empire, Dominium) by Jennifer Ridyard and John Connolly, I'm 90% sure it isn't. None of the cover variations match what I remember, and the plot is similar, but there are key differences from the plot I remember (namely that the female is alien and the male is human and not a prince).
Also, google keeps pulling up this series called The Resonance Trilogy (consisting of Resonance, Dissonance, and Harmonic) by A.J. Rosen (originally a massive hit on Wattpad before being officially published). But I literally can't find it anywhere. I remember reading it on my Amazon Fire tablet during Covid, and I remember it was at least a couple years old at that point, too. Published sometime in the 2000's or 2010's. I don't remember if I downloaded a free PDF of it at the time, or if it was free on the Amazon Kindle app that I had. Either way, that is the platform I read it on.
Any help or ideas would be much appreciated. I have thought about this series many times over the years, and it bugs me that I can't remember the title. Part of me is starting to think it was a fever dream or the Mandela effect or something. I also can't look at it on my tablet. I don't know where it is right now, and haven't had any luck looking for it either (it's also really old and slow, and I have no idea if it would even turn on at this point).