Milton frequently uses a dropped D (D-A-D-G-B-E) or violão de aço tunings. Chediak marks these clearly. Do not attempt "O Trem Azul" in standard tuning; you will break your fingers.
Finding a legitimate copy
Analyze page 17 of the songbook (if you find it). It describes the voicing shape. Milton favors the Lydian mode. Chediak shows you the specific inversion Milton uses—rarely the root in the bass. Songbook Milton Nascimento Almir Chediak Pdf