In the gas–turbine combustion system when the pressure and heat release rate oscillations are in phase, it can make combustor unstable due to satisfaction of Rayleigh criterion. Such unstable conditions are highly nonlinear and undesirable as it can cause catastrophic failure to engine. The experimental investigation was done to study the combustion dynamics response of a turbulent combustor to the parameters such as the location of the bluff–body, composition of the fuel, and global equivalence ratio. For this study, the circular shape bluff–body is used as a flame holder. bluff–body is when held closer to the air inlet, and the higher-pressure amplitudes were noted to be higher in contrast to when it is in much downstream. The combustion stability map was mapped for the global equivalence ratio, the primary combustion parameter. Lastly, the effect of varying syngas composition by CO/H2 ratios on acoustic oscillation was studied. The higher-pressure amplitudes and frequency oscillation were achieved at a higher concentration of CO. © 2021, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.