The Drones produce the background harmony. Three of the usual four drones are often set to play a background chord over which the melody is played on the chanter. A combination of notes of the tonic and dominant are used. Usually, tonic, dominant and octave-tonic.

Keyless Sets will have three drones playing the nominal notes of G, d and g. All other sets will have four drones.   This is because these sets have a chanter which can play in several different keys and the drones need to be able to be tuned to harmonise with them. The four drones will tune as follows-

• D and E

• G and A and B

• d and e

• g and a

This allows Gdg for the key of G, DAd or Dda for the key of D, Aea for A or A minor and Ebe for E minor.