Stage acoustic parameters aim to quantify the amount of sound energy reflected by the stage and hall boundaries and the energy decay over time. In this research, the effect of orchestra presence on parameter values is investigated. The orchestra is simulated by dressed mannequins, which have been compared with humans with respect to acoustic properties. Impulse response measurements were performed in a concert hall, a theatre, a rehearsal room, and in two orchestra pits. Conditions were empty stage floors, stage floors with music stands and chairs only, and floors occupied by the mannequin orchestra. Results show that the direct and reflected sound levels and the energy decay are significantly affected by the orchestra compared to an empty stage or a stage with chairs and stands only. Both the direct sound and early reflected sound levels are reduced by the orchestra with the distance. The late reflected sound level is reduced considerably more than can be expected based on Barron's revised theory. It can be concluded that measurements on a stage without the orchestra being present results in significant differences. A practical method is presented to perform a "musician friendly" stage acoustic measurement with a real orchestra.