iPhone 15 playing music randomly in the middle of the night?

Hello everybody. I have the iPhone 15 running the latest iOS 17.4.1.

Last night I left my phone on my desk, far away from my bedpost, having put the sleep mode on. Randomly, while connected to the charger (normal one-not wireless) at around 4 am, it started playing a type of Chinese/relaxing music (the type you hear in massage parlors). I do not listen to this music and have no playlist like this. It was way too far from me to have accidentally touched it. When I checked the control in the screen, no music was playing. I force closed all open apps but the music continued and I had to turn it off. Any idea what’s going on? It has happened before, again in the middle of the night but for few seconds.