▁bridge , ▁and ▁the ▁res embl ance ▁of ▁its ▁cont our ▁to ▁the ▁marine ▁speaking - tr ump et ▁of ▁the ▁Middle ▁A ges . ▁ ▁Const ruction ▁ ▁The ▁body ▁of ▁the ▁marine ▁tr ump et ▁is ▁generally ▁either ▁three ▁sides ▁of ▁wood ▁joined ▁in ▁an ▁el ong ated ▁triangle ▁shape ▁with ▁a ▁p eg box ▁at ▁the ▁a pe x ; ▁or ▁a ▁body ▁of ▁three ▁to ▁six ▁rib s , ▁a ▁front al ▁sound board , ▁and ▁a ▁distinguish able ▁neck . ▁ ▁In ▁most ▁cases ▁the ▁bottom ▁end ▁of ▁the ▁instrument ▁is ▁open ; ▁some ▁historical ▁models ▁use ▁sound - hol es . ▁The ▁single ▁string , ▁generally ▁the ▁D ▁string ▁of ▁a ▁c ello , ▁most ▁often ▁is ▁tun ed ▁to ▁the ▁C ▁three ▁oct aves ▁below ▁middle ▁C . ▁It ▁attach es ▁at ▁the ▁sound board ▁and ▁passes ▁over ▁one ▁foot ▁of ▁the ▁bridge , ▁leaving ▁the ▁other ▁foot ▁to ▁v ibr ate ▁freely ▁on ▁a ▁plate ▁of ▁iv ory ▁or ▁glass ▁set ▁into ▁the ▁sound board , ▁creating ▁a ▁br ass y ▁bu zz . ▁From ▁its ▁curious ly ▁irregular ▁shape , ▁the ▁bridge ▁was ▁also ▁known ▁as ▁the ▁sh oe ; ▁it ▁was ▁thick ▁and ▁high ▁at ▁the ▁one ▁side ▁on ▁which ▁rest ed ▁the ▁string , ▁and ▁low ▁and ▁narrow ▁at ▁the ▁other ▁which ▁was ▁left ▁loose ▁so ▁that ▁it ▁v ibr ated ▁against ▁the ▁bel ly ▁with ▁every ▁movement ▁of ▁the ▁bow . ▁A ▁string ▁called ▁a ▁guid on ▁is ▁tied ▁around ▁the