About chords in song books and sheet music:— Don't take them as necessarily authoritative. I've seen chord symbols in folk song collections that were fairly obviously worked out by jazz guitarists moonlighting for some music publishing company, who obviously knew nothing about folk songs. These "arrangements" were full of 6th, 9th, 11th, augmented, and diminished chords, completely inappropriate for the songs, and splattered all over the page; so much so that it was sometimes hard to pick out the basic I, IV, V harmonic structure by looking at the chords. Also, look out for song books that have both piano accompaniments and guitar chords. These are often done by formally trained musicians (sometimes the piano arranger himself or herself) who may know nothing about the guitar, but who tries to translate the piano arrangement into guitar chords. And if the song happens to be in Dorian or Mixolydian mode as a number of folk songs are, the result can be a real goat's breakfast. The chords in some song books you can trust, but always approach them with a twenty-pound grain of salt and be prepared to work out your own.

Don Firth