After the synthesizer in the beginning, the first time the main guitar riff
comes in (at about 34 seconds in) it is played by a piano only as it is for the next eight times playing those three notes (or until he starts singing when the guiar comes in.) By the way the notes for that are
Tabs guitar - WHO Baba O Reiley Chordsound to play your music, study scales, positions for guitar, search, manage, request and send chords, lyrics and sheet music