▁have ▁op us ▁numbers , ▁as ▁not ▁so ▁many ▁of ▁his ▁compos itions ▁were ▁published ▁during ▁his ▁lifetime , ▁so ▁number ing ▁by ▁op us ▁number ▁proves ▁quite ▁imp ract ical ▁for ▁Moz art ▁compos itions . ▁ ▁Sym phon ies ▁▁ ▁Moz art ' s ▁sym ph onic ▁production ▁covers ▁a ▁ 2 4 - year ▁interval , ▁from ▁ 1 7 6 4 ▁to ▁ 1 7 8 8 . ▁According ▁to ▁most ▁recent ▁investig ations , ▁Moz art ▁wrote ▁not ▁just ▁the ▁ 4 1 ▁sym phon ies ▁reported ▁in ▁traditional ▁ed itions , ▁but ▁up ▁to ▁ 6 8 ▁complete ▁works ▁of ▁this ▁type . ▁However , ▁by ▁convention , ▁the ▁original ▁number ing ▁has ▁been ▁retained , ▁and ▁so ▁his ▁last ▁sym phony ▁is ▁still ▁known ▁as ▁" No . ▁ 4 1 ". ▁Some ▁of ▁the ▁sym phon ies ▁( K . ▁ 2 9 7 , ▁ 3 8 5 , ▁ 5 5 0 ) ▁were ▁re vised ▁by ▁the ▁author ▁after ▁their ▁first ▁versions . ▁ ▁Child hood ▁sym phon ies ▁( 1 7 6 4 – 1 7 7 1 ) ▁ ▁These ▁are ▁the ▁number ed ▁sym phon ies ▁from ▁Moz art ' s ▁early ▁child hood . ▁ ▁Sym phony ▁No . ▁ 1 ▁in ▁E ▁major , ▁K . ▁ 1 6 ▁ ▁Sym phony ▁No . ▁ 2 ▁in ▁B ▁major , ▁K . ▁ 1 7 ▁( sp ur ious , ▁attributed ▁to ▁Leopold ▁Moz art ) ▁