The Tears of the Singers by Melinda Snodgrass (Star Trek #19, Good, 1984, Pb, 252 pgs, Pocket Books)

Cover has wear as pictured; pages are unmarked and lightly age-toned. ISBN 0671502840

Composer Guy Maslin joins the crew of the "Enterprise" to investigate the strange continuous song of the inhabitants of Taygeta, source of a dangerous spacewarp, and they discover that the destruction of the Singers is linked to the growing discontinuity.