After the centre drone has been tuned to the chanter reed, raising the others to the same height in the tuning joint or in line with it, does not always put the drones in tune. The reeds may differ materially in tone, and they must be brought to the same pitch by studying the sounds only. When the pipes are in tune all four reeds will chord. One may be stronger or harsher than another, and still chord with it. It is sometimes difficult for the learner to find the tuning mark, as it is very exact. Care and practice makes it easy. Young pipers should never play with their instruments out of tune, as this will accustom their ears to discords, and they will eventually be unable to tell when their pipes are in tune and when they are not. Suddenly moving the joints up or down to their full extent will be found capital practice for the beginner, as he cannot then fail to distinguish discords. He should then move them cautiously back as if feeling for something, and he will hear the jarring sounds gradually dying away until they blend in chord. In tuning, care must be taken that the pressure of wind on the reeds is exactly the same as when playing, otherwise discord is inevitable. Beginners should use reeds in the centre and big drones only, as the pipes will then he easier blown, as well as easier tuned. The practice can be discontinued when the player is able to blow freely. The further down the drones are tuned the sharper the sound becomes, and the further up the flatter or deeper. So if the chanter should have a sharp sound the drone must also be made sharp, or _vice versa_. All new reeds are generally sharp, and become flatter the longer they are played on. IV.—REEDS AND THEIR DEFECTS. Reeds have many defects, and nothing but experience combined with care will make a piper thoroughly at home in dealing with them.