During the sequence in this 2018 documentary by Werner Herzog and André Singer when Mikhail Gorbachev is mourning the death of his wife Raisa, a stunning unnamed lament can be heard playing.
It seems I'm not the only one looking for it! A certain Jake Charles Rees tweeted about it (presumably in vain) last November, which is great because this splendid fellow provides a clip! You'll need to turn on the volume in the video to hear it:
https://twitter.com/jakecharlesrees/status/1199092760285986817Is this music familiar to anyone? If not, is it possible to pick out some of the lyrics? I'd be eternally grateful for some help with this.