Oh, Mary Don't You Weep on Mandolin

This is only the first verse and chorus. Here's the full song on guitar: http://www.youtube.com/watch?v=HAukf_lh0b4
Rise Up Singing chapter: Freedom, p.63

Chords: D A / - D / G D / DA D ://

If I could I surely would
Stand on the rock where Moses stood
Pharaoh's army got drownded
Oh, Mary don't you weep

Chorus:
Oh, Mary don't you weep, don't you mourn
Oh, Mary don't you weep, don't you mourn
Pharaoh's army got drownded
Oh, Mary don't you weep