Great topic #Vesca !
Let's see: symphonic metal for the harder times: Nightwish,Xandria,Epica,Evanescence,Within Temptation and Kamelot.
Folk metal/fol rock such as: Blackmore's night, Faun,Omnia and Граи.
And as study-music, Celtic or Wiccan songs. Math works great with Moon Chants.
Lindsey Stirling,Celtic Women and Tarja Turunen are great now matter what mood I am in.
"The strength of the pack is the wolf, and the strength of the wolf is the pack" - Rudyard Kippling ⛤