Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The octave mandolin or octave mandola is an instrument which in construction is almost identical to a mandola but is slightly longer in scale (20"-23") and is tuned an octave below the mandolin (GDAE). It is an instrument of 4 double courses, each tuned a 5th apart. Usually the courses are all unison pairs but the lower two may sometimes be strung as octave pairs with the higher pitched octave string on top so that it is hit before the thicker lower pitched string.