Ritchie Blackmore picks his iconic intro riff with his thumb and index finger (despite using a pick in the verses, choruses and solo) for a more instant attack than a pick can give. It’s far from essential, though. Timing is a more important factor, so use a pick if you prefer.
Hold down the first three notes either with your first, third and fourth fingers or by barring across the 5th fret with your third finger. Make sure all the notes are clear and don’t ring out over each other. Take note of the rest symbols in the notation and make sure your guitar is silent during these moments.
These are basically the same powerchord shapes as used in the verse, just played in different positions on the fretboard. Be careful not to rush; each arpeggio is played at half the speed of the verse. Aim for a fluent, relaxed feel. Repeat the intro, verse, chorus and the intro once more before moving on to play the solo.
Play each two-note chord using one finger to cover both strings. A mixture of first, second and third fingers should get you through the section. Count to four to keep time. Most of the rhythms are based on eighth notes so try counting ‘1 & 2 & 3 & 4 &’ to pick these out.
For the pre-bend in bar 2, place your third finger on the 13th fret, silently bend the string up by a tone and then pick it, letting the note ring out as you release the bend. In bar 6, you have to pre-bend the string by a tone, lower the bend by a semitone, then re-bend back up. Listen carefully – it should be a semitone pitch change.