Sax's original keywork, which was based on the Triebert system 3 oboe for the left hand and the Boehm clarinet for the right, was simplistic and made certain legato passages and wide intervals extremely difficult to finger; that system was later improved with extra keys, linkage mechanisms, and alternate fingerings.
Sax'S OriGiNaL KEywork, whiCh waS BaseD on The tRiEbErT sySTem 3 oboE for ?tHe Lef?T hAnd aND ThE bOehM ClArInet foR tHE right, was siMplistic And madE cErtaiN legATO PAssAgEs and wIdE inteRvALs exTrEmeLy difFIcult To fingEr; ThaT sySTem wAs lAter imPRoVEd with extRa KeYs, LiNKaGe mEcHanismS, aNd AltERnate FingeriNgs.