System and method for reducing modal coupling of combustion dynamics

A system for reducing modal coupling of combustion dynamics includes a plurality of combustors (42), and at least one fuel injector (66) in each of the plurality of combustors (42). The system also includes structure for dithering a combustion instability frequency in at least one combustor in the plurality of combustors (42). A method for reducing modal coupling of combustion dynamics includes flowing a compressed working fluid (38) at a temperature to a plurality of combustors (42) and flowing a fuel to at least one fuel injector (66) in each of the plurality of combustors (42). The method further includes dithering at least one of the temperature of the compressed working fluid (38) flowing to the plurality of combustors (42) or the fuel flow to the at least one fuel injector (66) in at least one combustor in the plurality of combustors (42).