This is the riff from the David Bowie song "Rebel Rebel"
- It is a chord based riff using Dsus2 (an open D chord with the top string left open) and open E major.
It is important to play the chord shapes in full.
You could play the riff without them but it just won't sound right.
In bar one use your first finger to get the note on the 2nd string fret 2.
In bar two use your little finger to get this same note while holding down an E chord.