I mean, there can be ways to feature cameos from recording artists in a dramatic program and have it maintain its artistic integrity. Buffy the Vampire Slayer featured a nightclub in Sunnydale called the Bronze, and periodically characters would go to the Bronze and there would be a recording star playing. Sometimes very dramatic scenes would be happening out of view of the crowd while a song played (Aimee Mann's song "Pavlov's Bells" was featured this way in the episode "Sleeper"); other times, the episode would show a recording artist playing to a crowd at the Bronze while a montage of events played over the song (Michelle Branch's "Goodbye to You" was used to wonderful effect this way in the episode "Tabula Rasa").
The problem with trying to apply that idea to Star Trek: Enterprise is the fundamental premise of the show would not have allowed it, if the ship is the only United Earth ship in deep space and does not have a regular port it returns to on a consistent basis. You could probably pull something like this off if you're doing Star Trek: Voyager, Star Trek: Deep Space Nine, or Star Trek: The Next Generation, because the holodeck would allow for it in the case of VOY and TNG, and it's not at all implausible that Quark's Bar might host music acts on a regular basis on DS9. But with ENT, you've got the NX-01 alone, removed from almost all support infrastructure, with no regular port to return to.
The idea could work if either all of season one were set on Earth per Berman and Braga's original idea or if the NX-01 regularly returned to Earth -- there's no reason the 602 Club couldn't host music acts. It could also work if the NX-01 regularly returned to a port on an alien world (say, Rigel VI or something).
But of course the other big issue then becomes finding artists whose music is thematically appropriate to the kinds of stories ENT is telling, instead of just inserting "Backstreet's Back" or "It's Gonna Be Me" at the end of an episode with no regard for how it fits tonally or thematically in the show.
