Yep, like others have said, it's 100% normal. Usually, it's triggered by the sun coming up, but if you're turning lights on and making noise, that's plenty of a signal for him. I think cockatoos are about the worst in terms of greeting the dawn and farewell'ing the dusk, but most non-nocturnal birds do it to some extent, especially the dawn. It's flock bonding behavior - be happy that he cares!
Fun side story that's tangentially related: Lions sing in the sun, and out as well. How do I know this? Because at one point many years ago, while my then-SO and I were moving into our new little house out in the woods, we were sitting on the porch to take a break and watch the sunset after a full day of moving boxes, we suddenly hear a chorus of roars! Our dog freaked out, we freaked out, called the landlord to ask wtf... Apparently, the next property over was an exotic animal rescue, with a pride of sixteen lions! (Along with a couple of tigers and bears and other such beasties, rescued from those 'roadside circuses'.) Once we got used to it, it was actually really beautiful. I still miss the dawn and dusk chorus.