Iron Maiden

In the 80s, Steve Harris's band clearly turned the tide of metal music, building on the foundations laid by Black Sabbath, Deep Purple, Judas Priest, UFO, and others. The innovative use of the bass by Harris and the construction of complex tracks made their music very akin to prog, especially for some albums and certain songs, while still not neglecting the choruses, riffs, and solos that hold such importance in metal.

Many albums, but I would say six are essential in the formation with two guitars, and definitely one with the three-guitar setup.