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. Removing the mouthpiece by force could destroy the braces of the tuba. The flutina by Jeune and concertina by Wheatstone are similar to each other in tone and construction but these seem to match the accordion invented by Demian. When you put together these two instruments, it would resemble the diatonic button accordions which are still made in modern times. As time has passed, many keyboard and buttonboard systems were developed. Smaller guitars made of mahogany are very good for blues while nylon string guitars made with rosewood are for classical playing. Flamenco playing is best with nylon string guitars made with Spanish cypress which are thinner than the classical guitar. Acoustic guitar care The best way to keep the acoustic guitar from accumulating dirt is using a case for storage protection but you could also use a cover. A lot of banjo players prefers to use titanium or model railroad spikes to keep the string pushed down on the fret. Modern Banjo There many variations of the modern banjo. Increasing its popularity is the six-string banjo which is played like a guitar. The modern banjo s body, sometimes referred to as pot, has a metal ring, circular wooden rim, and a stretched head. In the 1980 s, the headless bass wad developed by Ned Steinberger and the Guild Guitar Corporation introduced the use of silicone rubber strings. Recently, bass guitar producers added digital modeling circuits in the instrument. Classic bass guitars Electric bass guitars has lasted for over 70 years and counting. Clavichord The clavichord is the most subtle and simplest among stringed keyboard instruments. It was popular in the Medieval, Baroque, Classical, and Renaissance eras. The clavichord flourished from the 1400 s to the 1800 s. It is rectangular with generally decorated and painted lid and casing. Its strings are stretched laterally from the tuning pins up to the hitch pins where there are dampers in the form of felt strips across the strings.