Howdy,

According to the Joan Baez songbook from 1964, Joan plays in Em with a capo at the first fret to sing in Fm.

As [Em] I walked [D] out over [C] London [Em or G] Bridge [Em]

One misty [Em or G] morning [D] early,

[Em] I over- [Em or G] heard a [D] fair pretty [Bm] maid

[C] Was la- [G] menting [B7] for her [Em] Geordie.

Hope it helps.

Allinkausay, Bill