On alto and better clarinets, and some soprano clarinets, key lined holes alternative some or all finger holes. The most common system of keys was named the Boehm system by its designer Hyacinthe Klosé in honour of flute clothier Theobald Boehm, but it is not a similar as the Boehm system used on flutes. The other main system of keys is termed the Oehler system and is used mostly in Germany and Austria see History. The related Albert system is applied by some jazz, klezmer, and japanese European folk musicians. The Albert and Oehler concepts are both according to the early Mueller system. Around the turn of the 18th century, the chalumeau was modified by converting one of its keys into a check in key to provide the 1st clarinet. This development 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 center register with a loud, shrill sound, so it was given the name clarinetto that means "little trumpet" from clarino + etto. Early clarinets didn't play well in the lower register, so avid gamers continued to play the chalumeaux for low notes. As clarinets more appropriate, 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 a lot of of makers added
more keys to get better tuning, easier fingerings, and a a little larger range.