Cello: a bass instrument with soft and full tone and good plucking effect. Viola: A alto instrument with a dark tone, which is often used to fill in harmony and rarely solo. Violin: A high-pitched instrument with bright and beautiful timbre, often solo. I have studied violin, but I haven't reached the level of solo yet.

Cello sizes are: 4/4, 7/8, 3/4, 1/2, 1/4, 1/8. Among them, three quarters are children's pianos. Piano lengths are 755 mm, 735 mm, 690 mm, 650 mm and 550 mm respectively.

Viola can be divided into viola and alto. Viola is about 15 and 16 inches. The alto violin is bigger, reaching more than 18 inch. The larger the fuselage, the better the penetration and the better the timbre effect. A good figure with little effect also has a good tone.

The dimensions of Viola are: 17 inch, 16.5 inch, 16 inch, 15.5 inch, 14 inch, 13 inch, 12 inch.

Body length: 430mm, 420mm, 4 10/0mm, 390mm, 356mm, 335mm, 3 10/0mm. ..

Violin length: 255mm size: 1/8 Suitable age: about 4-6 years old; Length: 280mm Size: 1/4 Suitable age: 7-8 years and a half or about 9 years old; Length: 3 10mm Size: 1/ 2 Suitable age: 10- 13 years old. Piano length: 335mm. Specification: 3/4 for age: a little younger adult or piano with a height of1.60m. Specification: 356mm Suitable for adults over .65m in height/kloc-0.

Adults don't always use adult pianos, especially amateurs. They often use oversized pianos, which affects their mastery of this instrument.