There’s absolutely nothing wrong with a good ‘straight up’ major or minor chord, particularly on acoustic guitar, but with a few little adjustments such as lifting a finger off or moving a note up or down a semitone, you’ll find that there are lots of other sounds available to you.
It’s true to say that a good song will often stand up on solo acoustic guitar, but that’s no reason for us to rest on our laurels. Players such as David Bowie, Pete Townshend, Joni Mitchell and Andy Summers have all created ideas that could be played with simple chords – but some depth and interest would be lost.
