AC/DC is blues derivative rock that has made them and The Rolling Stones billions of $ and is great music. You can't beat that. Tell him you know me someone who is in his mid 60s who still plays AC/DC and even comes from their hometown Melbourne Australia. I grew up with them. Angus Young the leader is pretty close to my age. I think he is doing great playing so well in only 3 months. My song "Last Call" was written to sound like AC/DC to fit in with our last bar set. And I play the lead guitar so I have no criticism of anyone playing in that style ... only admiration and you can tell him that from me. It is music you play from the gut. I have a feeling he will have no limits and will end up playing music in all sorts of styles.