To string a qin, one traditionally had to tie a butterfly knot ("shengtou jie" 『蠅頭結』) at one end of the string, and slip the string through the twisted cord ("rongkou" 『絨剅』) which goes into holes at the head of the qin and then out the bottom through the tuning pegs ("zhen" 『軫』). The string is dragged over the bridge ("yueshan" 『岳山』), across the surface board, over the nut ("longyin" 『龍齦』 dragon gums) to the back of the qin, where the end is wrapped around two legs ("fengzu" 『鳳足』 "phoenix feet" or "yanzu" 『雁足』 "geese feet"). Afterwards, the strings are fine tuned using the tuning pegs. The most common tuning, "zheng diao" 〈正調〉, is pentatonic: 1245612 in the traditional Chinese number system or "jianpu" 〔簡譜〕. Today this is generally interpreted to mean C D F G A c d, but this should be considered do re fa so la do re, since historically the qin was not tuned to absolute pitch. In fact the same tuning can also be considered as 5612356 when the third string is played as do. Thus, except when accompanied by other instruments, only the pitch relations between the seven strings needs to be accurate. Other tunings are achieved by adjusting the tension of the strings using the tuning pegs at the head end. Thus "manjiao diao" 〈慢角調〉 (slackened third string) gives 1235612 and "ruibin diao" 〈蕤賔調〉 (raised fifth string) gives 1245712, which is transposed to 2356123.