Led Zeppelin is indeed a Kohinoor among the gems of classic rock. Bands endeavour to create albums which sound different than each other wheras Zeppelin managed to create melodies in a single album sounding poles apart! This is the distinguishing foundation. Every song in itself is a new tale, an experience and an arrangement.
Next is the equation & chemistry among the band members.
Not far behind is the individual talent of each member:
Page & Plant: spectrum of notes, Infusion of influences: Blues, blue grass, middle eastern and Asia sub- contoinent classical music
Jones: Art of playing various instruments and creating a colourful rythm section
Bonham: The power, the might, the speed, the finesse: The Sound of Zeppelin was born