A combustor and a method involving burner mains structurally configured to damp vibrational modes that can develop under high-frequency combustion dynamics are provided. The combustor may include a carrier (12), and a plurality of mains (16) disposed in the carrier. Some of the mains (labeled with the letter X) include a body having a different structural feature relative to the respective bodies of the remaining mains. The mains with the different structural feature may be selectively grouped in the carrier to form at least one set of such mains effective to damp predefined vibrational modes in the combustor.