Four notes. The descending chromatic bass line. And a Harmony Sovereign acoustic guitar recorded with little air. That is how the most imitated arpeggio in the history of rock was born.
There was a progression that any record store in the 80s knew: Am, Am/G#, C/G, D/F#. People would walk in, grab an acoustic from the display, and start playing it. The legend says some stores had a sign: "no Stairway".
The chosen instrument
Page used a Harmony Sovereign acoustic, not an electric one. The acoustic gave a short, crystalline sustain that the recording needed — the song grows from zero to infinity over 8 minutes, and the beginning had to be intimate.
The arpeggio
The first four notes of the arpeggio (A-E-B-E in the first measure) are simple. What makes them memorable is the descending bass line: A → G# → G → F#. That chromatic box is the harmonic signature of the entire song.
Without the acoustic guitar at the start, Stairway isn’t Stairway. The electric guitar of the final solo only works because the acoustic at the beginning paved the way.
