... Amon Amarth ... 'mainstream' metal bands like Iron Maiden, Metallica, In Flames and Mastodon (Leviathan was sweeet). ... Baby Metal
I have to admit that I've watched Baby Metal youtube videos a nonzero amount of times
I've also seen Mastodon live a few times (and also thoroughly enjoy Leviathan). But I am surprised that Amon Amarth is your jam, if you don't like gruff vox!
Primordial -
To the Nameless Dead
Progressive black metal band with a haunting vocal style that transitions from singing to rasping mid-word at times. The songs midpaced epicness evoke a forlorned Amon Amarth for me
Mercenary -
The Hours That Remain
Power/melodic heavy metal ventures into extreme metal songwriting
Devin Townsend -
Ocean Machine
Devin Townsend, former Steve Vai vocalist, puts out a lot of progressive metal albums (and this is my favorite).
Arcturus -
The Sham Mirrors
One-of-a-kind avantgarde black metal/industrial craziness. One later track features Ihsahn of the band Emperor (and has very harsh vocals).
Soen -
Cognitive
Obviously takes cues from Tool/A Perfect Circle, but has a lot of variation in their songs.
Pain -
Dancing with the Dead
Pop metal from Hypocrisy's Peter Tagtgren. This might scratch your baby metal itch. Cannot find a full album link of Rebirth, but also great:
End of the Line /
On and On
Therion -
Sirius B /
Lemura
Hard to believe this used to be a mostly standard death metal band. Double album that is closer to listening to an opera/symphony than a metal cd.
If you like the death metal approach of Amon Amarth and In Flames, also make sure to listen to some
Dark Tranquillity if you haven't!