Mist

When i was first time listen their songs i almost fell off my chair.

Of course. Objectively we can't say that one band create whole new genre of music. Several hard rock and punk rock bands, single musicians participated in the creation of heavy music. Thin Lizzy was close to playing classic metal music. I recommend you to listen their next album "Bad Reputation", where you can find a few tracks in style of heavy music. Also album"Chinatown" include 2 tracks and "Renegade" with "Angel Of Death". John Sykes joined Thin Lizzy, so guitarist playing much harder and faster. "Thunder and Lightning" was clean metal album. Thin Lizzy is very underrated band with huge influence on 80s NWOBHM playing style. On the internet they often do not write about it (in magazines yes, for example in my country ) so you see by yourself. When we add later elements but in the beginning all playing similar. I knew that Uriah Heep also add heavier sounds. Somewhere mentioned: 1971 "Bird Of Prey" compare this with BS and later style of playing. BS influenced metal scene. Many parts of metal music are borrowed from other 70s bands especially powerful vocals and more complicated structure of composition.

Many of the hearers thinks that first heavy rock* track would be Black Sabbath by the same named band or Judas Priest or Blue Cheer or some other. But specialists or musicians said that BS plays in blues standards (rythm and many other), except of doom, słow, łow tuned guitar sound. In my opinion first truły heavy rock (or metal) composition was Emerald by Thin Lizzy, released in 1976. It has all elements: heavy drums, crazy solo guitar and perfect melodic twin guitars that many bands use in later times in their tracks. *why i wrote heavy rock? because if you ever watch or listen nowadays interviews with musiacians from older bands 80s (for example series "metal Evolution"), musicians laughs when they hear description "heavy metal" they never called their music like that. "Heavy metal" was invented by journalists in that time, same as NWOBHM. So I agree with creators of that music genre. Maybe you knows other good old tracks? Or you have other opinion?

Gamma Ray - Dethrone Tyranny Kreator - Gods of Violence