A British mystery writer -- a certain Philip Marlow -- who's suffering from acute psoriasis and arthritis while the torch song ''I've Got You Under My Skin'' plays in his head? This is the stuff of TV legend: When The Singing Detective first aired in the U.S. in 1988, the British writer Dennis Potter's six-part BBC miniseries blew minds -- a hallucinatory combination of hospital drama, mystery story, and music-hall razzle-dazzle, all of which may or may not be taking place entirely in the frazzled head of bed-bound Marlow, played with splenetic passion by Michael Gambon.
Now out as a three-DVD package to capitalize on a new American movie version starring Robert Downey Jr. that opens this fall, the original ''Singing Detective'' may be the finest TV movie ever made. The package includes a witty commentary track, in which director Jon Amiel (''Entrapment,'' ''The Core'') says that Potter's recurring themes are ''money, sex, venality,'' and two in-depth profiles of Potter, who himself suffered from the maladies that beset his Marlow. The author, who died in 1994, says in one that he'd written ''a detective story about how you find out about yourself'' -- that is, how suffering and resistance form your character.
''I certainly suffered for this art,'' says a jovial Gambon by phone from London. Just applying the psoriatic skin makeup took two hours every day, and ''we could only film for two hours at a time, because the stuff melted under the heat of the camera lights.'' Gambon says Potter, whose hands were so gnarled by his afflictions that he had trouble picking up a pen or cigarette, ''showed me how he handled the little but crucial things in life -- he was very unself-conscious and helpful about it.''
''Nowadays, the BBC would never air anything this daring -- only HBO would be able to handle the intensity of this work,'' says Gambon, who replaces the late Richard Harris as Dumbledore in the next ''Harry Potter'' movie. ''Even before ['Detective'] first aired, we knew Dennis had created something marvelous -- deeply funny and disturbing.'' Fifteen years on, it remains skin-crawlingly good.