Surna is a national wind instrument in China, which was introduced from Persia. Paintings played by suona appeared in the murals of Qizil Cave Temple in Xinjiang during the Western Jin Dynasty, and spread among the people in China at the latest in the16th century. Suona is bright in tone and loud in volume. This pipe is made of wood and shaped like a cone. The upper end is equipped with a copper tube with a whistle, and the lower end is covered with a copper bell (called a bowl). So it's also called trumpet. In Taiwan Province Province, it is called Advocacy, and in Guangdong, it is also called "Eight Tones". Folk musical instruments widely circulated in China. The pronunciation is loud and clear. In the past, it was mostly used to accompany folk song blowing parties, yangko parties, drum music classes and local folk operas. Through continuous development, it has enriched the playing skills and improved the expressive force, and has become a unique solo instrument, which is used for national band ensemble or opera, song and dance accompaniment.

Trombone is a brass instrument that uses telescopic tube instead of piston, so it is also called telescopic trombone or lens barrel. Originated in the middle of15th century, 1520 was improved to its present shape by Menschel. This is the earliest musical instrument (except drum) made into its present shape. At first, it was mainly used as an instrument in the church music brass ensemble, and/kloc-0 was adopted by the orchestra in the middle of the 8 th century.

The trombone consists of two parts: 1. The cylindrical horn tube with a cup-shaped bell mouth begins to expand at the lower third to form a bell mouth; 2. Insert the U-shaped telescopic tube in the first part of the pipeline. The player holds the instrument in his left hand and the telescopic tube in his right hand. Pulling out or retracting the telescopic tube will also change the length of the trombone, which can play overtones of different tones. The trombone telescopic tube has seven handles, and each extension lowers the handle by a semitone.

There are many kinds of trombones, mainly alto trombone, alto trombone and bass trombone. Bach, Gluck, Mozart and Beethoven all wrote trombone trio with these three trombones in their youth.

There are two kinds of tenor trombones, bE and f, which were very popular in16-18th century and were used as tenor instruments in brass instruments. At the beginning of19th century, it was gradually used less, but at the end of19th century, alto trombone was often used to play high but weak sounds.

The alto trombone in bB key is the most typical trombone, which mainly uses sounds above two overtones. Some sounds can be played with two or more phonemes. When using the seventh position, the telescopic tube is the longest and most difficult to play, so try to avoid it, but this position must be used for the bass.

There are two kinds of bass trombones, F and G. The former is mainly popular in Germany and Central Europe, while the latter was widely used by British brass bands from the early 7th century to the 1950s. The bass trombone is very long, so the pronunciation is a bit slow, and the basic sound is difficult to play. Because the telescopic tube is too long, a handle is often installed on the telescopic tube in order to hit the lowest handle.

In addition to the above three trombones, there is also a trombone with tenor and bass, which is widely used at present. This trombone was written in 1939. An additional trombone with a length of about one meter is added to the alto trombone in bE key, and the piston controlled by the left thumb (the so-called "four-degree piston") connects it to the basic trombone, so that the instrument is lowered by four degrees to become the bass trombone in F key. When the "four-degree piston" is applied, the pipe 1 becomes quite long and the sliding distance between the handles of the telescopic pipe increases, so only six handles can be used. The "four-degree piston" is not only needed when playing bass, but also sometimes played. When using the "four-degree piston", the pronunciation will lose some distinctiveness.

In addition, there is a piston trombone, 19, which was first created in the 1920s and is easy to play. It is rarely used now. When playing phrases that need to change positions continuously and quickly, the piston trombone is more convenient than the telescopic trombone.

I hope it helps you.