Sure, they're great. I'd probably file them under garage rock more, but they're still solid picks. If I had to round out the top four ultimate hard rock bands myself I'd think about acts like The Cult, Motorhead, Def Leppard, Rose Tattoo, maybe ZZ Top.

Nice one- AC/DC are still putting out new material so let's have them in there as well!

AC/DC and Guns N Roses are enough by themselves frankly. A lot of people will want to auto-include Led Zeppelin, but to me they're really more just hippies on the heavier end of blues rock than poster boys for hard rock.

Levisoto

You can advocate the pursuit of a meaningful life without having to reframe the concept of happiness as a strawman. Happiness is low-hanging fruit for derision because it can be so silly and trivial but it is the antonym of suffering and the goal of much early philosophy, all of which is as compatible with the pursuit of higher ideals as much as it with the reduction of psychological despair. Imho this article uses "happiness" when it is really just talking about "hedonism."

Maggot Brain is not a solo. It's an instrumental with a guitar as the lead, like a jazz song with a sax as the lead instrument. That said, most people don't know or care about the difference and even some musicians will argue the point. Either way, Maggot Brain is fantastic.

You can't go wrong here- all of Tarkovsky's films are available free on YouTube with English subtitles if you fancy trying another. They are all equally spiritual and meditative. My favourite is Mirror. There's a sub r/Tarkovsky