I'll probably get flamed for this, but I actually wouldn't have minded a radically different approach to the sound of Enterprise. Guitars and synth in there, with the orchestral strings pushed even further into the background.
There's harmonica and a bit of Americana during "Broken Bow" when Archer is thinking about the past, but it could've gone in even more experimental directions.
Dennis McCarthy provided some fine soundtracks, but a Star Trek prequel absolutely needed to move away from the classical scoring, that tries not to be intrusive like Voyager or Deep Space Nine.
Incidental music has appeared before, like Steppenwolf in Star Trek: First Contact and the Beastie Boys in the JJ Abrams picture. I'm not sure how Enterprise would've acheived that. Probably a bit like Movie Night, where the crew can be free to listen to whatever music they like in their quarters off duty. That kind of reinforces that the show is closer to our present day than the 23rd or 24th Centuries and next centuries' popular culture isn't all that different from our own.
Then you've basically got that whole Vic Fontaine aspect of Deep Space Nine, where a guest character gets the main cast to join in singing easy listening material.
It'd be very dangerous to pick whatever's "now", only for that artist or band to disappear and never be heard from again. I'd certainly lean toward Rock more than Pop or R'n'B. They have had to pick something iconic, or an artist that's already well-established but maybe one of their lesser remembered songs. Preferrably with lyrics that creatively fit into the story or else it's basically just product placement.
I'm not down with teen sensation, One Direction being in the Mess Hall, for absolutely no reason other than it panders to a certain demographic. That's the current equivalent isn't it? Selling out. This time next year, that fickle age group won't even remember who the f--king hell they were.