The 12 string guitar is similar to a 6 string guitar, except with 6 pairs of tuned strings that provide a full, warm, and rich sounding tone. The strings of the lower four pairs are tuned in octaves whereas those of the upper two pairs are tuned in unison.These guitars are a little harder to play than a 6 string, particularly due to the string tension and added number of strings. 12 string guitars are known for their richer and more resonating tone.