I WAS that kid (only I was 15 and it was 1985). My neighbor came over and asked my mother (they grew up together) if I could fill in with his band. Their bass player had quit with no notice. One fill in became a few fill ins and next thing you know I am playing in clubs all over NC and VA with a band of 30 and 40 somethings at 15. That's how I got started with this crazy mess. It worked fine for us. Give the kid a shot. Just be CLEAR and UP FRONT about what you guys do and what you aren't going to do (like drop the country songs). 19 year olds have the attention span of a gnat! Just keep him on track and you should be fine. It should be a shot in the arm for the band!