Two of my favorite groups personally are the Mexican trio Camila and their compatriot duo Jesse y Joy. One of the reasons I like them so much is that I can pretty much play any of their songs, and most videos too, in class. They're fairly positive & upbeat as far as content goes. Right now I'm liking Abrázame by Camila (you've got some tú command, infinitive after preposition, and subjunctive for influence in there). I think my favorite Camila song is Coleccionista de canciones, which we use in Spanish 1 for the repetitions of tú and in Spanish 3 for talking about professions without articles ("ella es coleccionista de canciones"). The video for Coleccionista is pretty cool too. Curiously, my students also like Solo para ti by Camila, because it's very N'sync-y.
And of course, Jesse y Joy are a big hit. Espacio sideral is one of my best successes in class and great for object pronouns. On the slow side, my students also like Mi sol (you can ignore that video clip and just listen to the song-far as I can tell there isn't an official video), which is fantastic for eres. We use Volveré in Spanish 2 for future verbs. I like Quiero conocerte, and use it occasionally for conocer, but my students don't really like it.
Anyway, if you're wondering where to start with music in your class, start with Jesse y Joy and Camila and you can't go wrong!