Traditional heavy metal, which includes NWOBHM (New Wave of British Heavy Metal)
Judas Priest. The second most important band to metal after Black Sabbath.
Sinner
https://www.youtube.com/watch?v=FrdEuEWBIFQ
Motörhead. Lemmy didn't consider his band to be metal and I can see why but they are inseperable from metal. Their influence cannot be overstated.
Stay Clean
https://www.youtube.com/watch?v=jvScReIRZOA
Rainbow
Stargazer
https://www.youtube.com/watch?v=rVXy1OhaERY
Scorpions. Not a metal band but they had metal songs.
Dark Lady
https://www.youtube.com/watch?v=Z_36fjL5Z84
Diamond Head
It's Electric
https://www.youtube.com/watch?v=NzMnmIGZPUE
Satan
Trial by Fire
https://www.youtube.com/watch?v=74Nei5Axde4
Mercyful Fate
Don't Break the Oath
https://www.youtube.com/watch?v=LWCOqNHzM0k
Raven
Hard Ride
https://www.youtube.com/watch?v=pE62kMm2XmI
Angel Witch
Atlantis
https://www.youtube.com/watch?v=EaPJTXI2ZLM
Saxon
To Hell and Back Again
https://www.youtube.com/watch?v=Um-6mGZxqo8
Tygers of Pan Tang
Gangland
https://www.youtube.com/watch?v=cX92w-WEiQ4
Girlschool
Demolition Boys
https://www.youtube.com/watch?v=JhAX96Lr8Y8
Holocaust
Death or Glory
https://www.youtube.com/watch?v=sxvR3YZQyoA
Blitzkrieg
Blitzkrieg
https://www.youtube.com/watch?v=Ll4Ij58497Q
Tank
Run Like Hell
https://www.youtube.com/watch?v=wolPKDKdN_U