Cossack choirs and other Russian folk music
After the disaster involving the Alexandroff chorus, the two Cossack choral groups I would recommend listening to would be the Kuban state choir and the Pyatnitsky choir.
You can search youtube for all Cossack choir music by pasting -- казачий хор -- into the search box.
I know, you could paste "cossack choir" into a search as easily, but I have the feeling that I'm turning up more interesting stuff searching in Russian...
The Kuban choir would be кубанский хор and
the Pyatnitsky group, пятницкий хор
A few items I'd recommend:
Kuban Jubilee Concert:
Pyatnitsky choir "Ой, со вечора, с полуночи",
There are two common Russian songs about the Cossack chieftain Stenka Raizin. One is a drinking song about Raizin drowning the Persian girl in the Volga river which isn't notably better or worse than most drinking songs:
The other is a very pretty sort of a thing about a dream or premonition which the chieftain had.
Pelagea's version:
Multitudinous other versions, search youtube on -- ой да не вечер --
The saber dance song:
There is a folk group I listen to which isn't exactly Cossack music but sounds like a mixture of Cossack and Irish music, i.e. Otava Yo / Отава ё:
Inpromptu concert/live stream:
Another sort of a thing which I enjoy listening to would be Russian or Ukrainian psalter music. Russians call that goosli / гусли, which is one of those words which exists only in plural form. That was the classical instrument of minstrels in past ages and the instrument which Sadko plays in Rimsky-Korsakov's opera of the same name, search on -- гусли:
The Ukrainian version is called бандура / bandura
There's more to Russian folk music than that of course, but that might do for starters.