A combustor includes an additively manufactured (AM) combustor body including a one-piece member including: a combustion liner defining a combustion chamber. A resonating tube is part of the AM combustor body and is configured to dampen acoustic pressure oscillations of combustion gases in the combustor. The AM combustor body includes a plurality of parallel, metallurgically bonded layers, such as sintered metal layers. The resonating tube includes a body defining a resonating chamber and a resonating tube neck having a first end in fluid communication with the resonating chamber. A second end of the resonating tube is in fluid communication with an annulus or the combustion chamber.