An old 16th century english traditional in the version of Paul Simon, or rather - as some sources say - of English folksinger Martin Carthy, who became known as "the man who gave away 'Scarborough Fair'" .
Looks like Dm - but it is Dorian Mode D
Attention: Low G
Beautiful song. In this arrangement I tried to integrate and mimic the „spheric“ guitar accompaniment phrase (in the intro and between the sung parts). Unfortunately this works only in Low G tuning.
At the end of the third line, there is an alternative fingering indicated in red. That one might be more convenient, if you want to maintain the barre position. If you prefer a „forward-looking approach“ (always get prepared for the subsequent chord), then use the standard fingering.