In a recently constructed concert hall in The Netherlands (14400 m[sup 3], 1250 seats), problems were encountered with solo piano performances. Music critics wrote that the instrument sounded unclear and appeared to be swimming in space. A 52-m[sup 2] on-stage wooden reflector and a 90-m[sup 2] curtain along the front wall, both removable, were applied to increase clarity C[inf 80]. This satisfied the critics. The acoustic effectiveness was measured by making KEMAR head recordings of short piano fragments, replayed by a Yamaha Disklavier, at various listening positions in the hall, both with and without the reflector and curtain in place. Two-alternative forced-choice discrimination experiments between comparable stimuli, with and without the provisions, were performed with listeners using insert earphones. The results showed that only a few listeners were able to score significantly above chance level for a few music fragments and recording positions. The average score over all listeners, music fragments and recording positions, however, was only 57% correct. This suggests that the apparent success of the reflector/curtain combination is attributable to factors other than purely acoustical ones.