Irish actor?

Rating: 7/10 (22 March 2018)

Overall, I like this movie. Jeff Bridges paints a believable portrait of a has been, drunken singer. He drives from place to place in a 30 plus year old Chevy Suburban singing in one dive after another while his protégé has become famous and travels with an entire caravan of top-of-the line motor coaches. What has me scratching my head though is why is an Irish actor (Colin Farrell playing the aforementioned protégé), cast as an American country singer? This is a case of severe miscasting. Why didn't the filmmakers have a real, American country singer play that part?