Keith Richards' tone on Start Me Up is the sound of rock and roll rhythm guitar stripped to its essence. A Telecaster in open-G tuning (with the low E string removed, making it a 5-string guitar) through a cranked Fender Twin Reverb. The open tuning allows Richards to play full, ringing chords with a single finger barred across the fretboard, creating a big, open sound. The Twin Reverb's clean headroom preserves the jangly brightness of the Telecaster, while the slight natural breakup from playing hard gives it attitude.