改弦易辙

gǎi xián yì zhé

change of string, move out of rut (idiom); dramatic change of direction

to dance to a different tune

改

gǎi

to change

弦

xián

bow string

易

yì

abbr. for 易經|易经[Yi4 jing1], the Book of Changes

辙

zhé

rut; track of a wheel (Taiwan pr. [che4])