Thirty top conductors have signed a letter demanding that improving acoustics at London’s South Bank should be the top priority in a renovation. “The roll of names includes such sworn enemies as Daniel Barenboim and Christian Thielemann; Riccardo Muti and most other Italian maestri; Simon Rattle and several of his less guarded professional critics. What unites them is a concern for London’s premier concert venue and a fear that it may suffer as a result of declining political regard for classical music and the general decay in British arts policy.”