They are totally with the band, even on cross-country trips.
If you're Jake Gyllenhaal and you hear that one of your favorite bands, Mumford & Sons, is going on a train tour of the United States, you tag along. You know, just for fun. Really, who's going to say no? Gyllenhaal joined the band in California and rode with them at least as far as Marfa, Texas. Is this how A-listers do spring break?