Led Zeppelin-Led Zeppelin II (1969)

After their huge record debut, Led Zeppelin published the same year (to be exact ten months later), their second album entitled "Led Zeppelin II", consolidating their initial proposal with this new album.
If it were to become a typically heavy metal album, if it would lay the foundations of what this genre would later represent in music; blues sifted by powerful guitar riffs, heartbreaking vocals, dense and forceful bass and drums rhythms and above all a challenging and energetic attitude.
This is the album where the band begins to lay the foundations for what would later become Led Zeppelin.
Without leaving behind the blues influences and the small approaches to folk, Led Zeppelin printing more hard rock and giving it much more prominence, "Whole lotta Love" or "Heartbreaker", are a good example of it, on the contrary "Ramble On" or "The Lemon Song" are the continuation of the style shown on their debut album.
For many, this is the album that began heavy metal and hard rock, and that would definitely establish them as one of the great rock bands in the world.