This advancement is usually attributed to German instrument maker Johann Christoph Denner, though some have recommended his son Jacob Denner was the inventor. This tool played well in the middle sign up with a loud, shrill sound, so it was given the name clarinetto which means "little trumpet" from clarino + etto. Early clarinets didn't play well in the lower check in, so avid gamers persevered to play the chalumeaux for low notes. As clarinets enhanced, the chalumeau fell into disuse, and these notes became referred to as the chalumeau sign up. Original Denner clarinets had two keys, and could play a chromatic scale, but loads of makers added more keys to get more suitable tuning, easier fingerings, and a slightly larger range. The classical clarinet of Mozart's day usually had eight finger holes and five keys. The next major development in the history of clarinet was the discovery of the fashionable pad. Because early clarinets used felt pads to cover the tone holes, they leaked air. This required pad lined holes to be kept to a minimum, restricting the variety of notes the clarinet could play with good tone. In 1812, Iwan Müller, a Baltic German neighborhood born clarinetist and inventor, constructed a new type of pad that was covered in leather or fish bladder. It was airtight and let makers augment the number of pad coated holes.