I think it's important to stick to one genre, if you try and please all the people you'll please no one, in the band I'm in covers are chosen by consensus, but if someone really doesn't want to do a certain song we don't do it, after all if someone refuses to learn a song what can you do? besides kick them out the band, I've recently done this, the singer wanted to learn Ruby Soho by Rancid, but we'd already tried Timebomb, a more popular song, according to Spotify streams, by Rancid and it flopped and got dropped, so I wasn't going to waste my time learning it