I don't recall seeing anyone test the Pocket 2 with a good quality stereo external mic. The P2's internal mics are excellent and provide an immersive stereo image, but on a windy day you have to resort to wind noise reduction processing, which is a poor substitute for a 'dead kitten'. So here's my test of the P2 with an audio-technica stereo shotgun mic. I'm pleased with the result - the mic input on the 'do-it-all handle' accessory has a flat frequency response across most of the audible spectrum so the end result will depend more on the mic quality than on the P2 quality.
For this mic, I needed the +20dB setting on the audio input, and added another 12db of gain across the whole of the edited video. But this indicates that there should be no problem recording loud music with this rig.
The visual element comes from a walk in a suburban Melbourne park on the second day of summer here in Australia. You won't see many people about - during the lockdown, the parks and streets were full of people taking the opportunity to get some exercise (which was permitted subject to conditions) but now everyone is allowed out - nobody is to be seen...
Video was 2.7k30p, auto. Not only has the sound come out well, so has the video itself! P2 works well in summer sunshine.