This
In the dark on my own
I do a class called Body Combat (martial arts moves, but done to music) at the gym twice a week and in one of the releases, the Muay Thai track used the Excalibur version of O Fortuna (ie the third verse). I'd always loved it, so I actually set about learning the lyrics for it so I could belt them out when doing that track
Marci, the instructor used to get everyone just going "La la la" along with the music, but I know how to project my voice, so I could equal her on the mic and everyone else singing in volume