French Horn
Although evolving from the early valveless hunting horn, modern French horns now have three or four valves. Single horns play in either Bb or F and are often used as starter instruments due to their lower weight. Double horns combine two distinct sets of tubinhg linked via a fourth valve to provide a full Bb and F facility. A compensating horn also plays in Bb and F but has some elements of tubing in common to give a weight (and cost) advantage, but often at the expense of readily accurate tuning.