e. , it is hard to have enough spring force to close the opening securely. The body of a trendy soprano clarinet is competent with a large number of tone holes of which seven six front, one back are covered with the fingertips, and anything else are opened or closed using a set of keys. These tone holes let the player produce every note of the chromatic scale. On alto and bigger clarinets, and some soprano clarinets, key lined holes substitute 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 fashion designer Theobald Boehm, but it is not a similar as the Boehm system used on flutes. The other main system of keys is named the Oehler system and is used mostly in Germany and Austria see History. The associated Albert system is utilized by some jazz, klezmer, and eastern European folk musicians. The Albert and Oehler programs are both based on the early Mueller system. Around the turn of the 18th century, the chalumeau was modified by converting one of its keys into a register key to supply the 1st clarinet. This development is typically attributed to German tool maker Johann Christoph Denner, though some have suggested his son Jacob Denner was the inventor.