Is there anyone who's not loath to kick this tired old troika? Crosby, Stills and Nash, after all, saw us through '60s upheaval long enough to plant the seeds of serious '70s downheaval; their songs today are maddeningly mellow, infinitely hummable and ultimately uninspiring.

"Daylight Again" is as sweetly sincere as music can get and still be called rock and roll. Playing the role of sage ex-revolutionaries to the hilt, CS&N advise us on how to get along with our girlfriends ("Turn Your Back on Love"), how to age gracefully ("Wasted on the Way"), how to deal with emotional problems ("Into the Darkness"), how to set a mainsail ("Southern Cross") and how to achieve peace on earth ("Find the Cost of Freedom"). One cannot doubt their conviction nor their intimate knowledge of harmonics, but their sublime determination to be innoffensive is, well, offensive at times.

Listening to this album at home, under a heavy hangover, is conceivable -- sort of like an est session, except you could visit the bathroom whenever necessary. But enjoying it under any other conditions would require hardcore devotion. As their former colleague Neil Young would say, ''It's better to burn out than to fade away.'' If these guys get any paler, they'll evaporate. THE RECORD, THE SHOW THE ALBUM -- Daylight Again (Atlantic SD19360.) THE CONCERT -- Thursday at 7:30 at Merriweather Post Pavilion.