In 1978, one particular paper in JASA by Harold Marshall, D. Gottlob and H. Alrutz titled: "Acoustical conditions preferred for ensemble" inspired the author and other researchers to investigate the acoustic conditions experienced by musicians on concert hall stages. The research carried out since then has involved subjective assessment by musicians playing in simulated sound fields as well as in real halls; but also purely objective investigations have been reported. After one third of a century, it seems appropriate to summarize what we have learned and where we still need more knowledge. The paper will summarize major contributions to the field, discuss the differences in opinion in view of the limitations associated with different experimental approaches, and finally address the challenges related to meeting working environment requirements recently enforced by law in Europe for limiting the sound exposure levels of musicians.