I think we all have to accept that this season is going to be complete bats#%t! crazy all the way along, with lots of broken 4th walls. This was definitely a better episode, and had some nice touches (including the awesome sonic silencing effect), but it was still superficial in my book - if felt like Glee, or something; this week, we're doing The Beatles / 1963, giving it lip service, and then moving onto something else.
Did anyone else think this episode might have been better served as being no. 8 or 10, with some hints and build up about the end of music dropped all the way through (ala the movie Yesterday). In the end, it felt like a promising villain and an apocalyptical premise rushed headlong into to soon; The Doctor can't face this threat; can't beat it; it's luck. But in the end, he does it quite easily, whilst also playing the piano like a maestro.
For me, it's just being camp for camp's sake. The best Doctor Who stories were always the darkest, most mysterious, most ingenious (Blink, Listen, Heaven Sent). At the very least, they took their time, used the slow build approach, and were heavy in atmosphere and setting the scene. These episodes just seem so impatient to get to every plot point or twist, and then on to the next. As long as everything is brash, loud, and colourful, the hope is that no one notices the seams. It's still a notch up on Jodie's last 2 seasons, but I fear this may be a superficial happy meal of a season with few genuine highlights to revisit in the future.