The scrupulous approach to making double reeds is a huge factor in producing quality musical sound. Popular culture The sound of a duck is frequently compared to that of the oboe in popular culture. It has been used to play the character of a duck in Peter and the Wolf of Sergei Prokofiev. Based on research, the oboe, clarinet, and flute are viewed as instruments that are on the feminine side. A change to the octavin During the young twentieth century, it would seem that the odd shape of the octavin has caught the negative attention of a few instrument designers. It is would be strange right now but some straight octavins were created which made it look like a clarinet at first sight. But the conical shape gave it away. The differentiating characteristic of the trombone is a telescope-like slide which is controlled by the player to change pitches with the exception of the valve trombone with three valves. Similar to other brass instruments, the vibrating lips of the player makes the air inside the trombone to vibrate and this produces sound. Fretting generally gives limitations on the playing range because it is impossible to produce the sound of the fretted notes at one time. There are times that the player has to cut a note by releasing a key just before it completes its full sound. There are also instances wherein the player has to omit a note but this is quite rare. Dismantle the valves one by one, put three oil drops, and place the valves back. You would know that the valve is not in the correct place if you blow hard but the air is blocked. Draw the major tuning slide out to make the tuba longer and thus lower the pitch. Push the major tuning slide in to make the pitch higher. Because it originated from Naples, the mandolins built centuries back are called Neapolitan mandolins. These have bodies which are almond-shaped and have bowled backs. Its soundtable which is curved provides greater string tension. It has a bridge which is a movable piece of ivory or hardwood placed in front of pins holding the strings.