IT PROBABLY did not happen; but why let something as petty as the truth get in the way of a ripping good yarn - or a fine radio documentary? Fats Waller and Al Capone (Radio 2, Tuesday of last week) was both: a great story and great radio, with just the right balance of melodramatic legend and scholarly scepticism.

The anecdote that justified the title is difficult to substantiate: that the jazz superstar Fats Waller was kidnapped in 1926, during a stay at the Sherman Hotel, Chicago, by flunkies of the notorious Al Capone, in order to play for the mafia boss's birthday party.

Three long days and nights later, Waller was released, his pockets stuffed full of $100 bills. The story originates with the jazz pianist's son Maurice, and may have been spun to mask the more mundane truth of Fats's visits to Chicago - that they often involved scrapes with authority as a result of the many alimony claims against him.

"Kidnapping" is probably not the right description. As Kurt Elling's commentary reminded us, the jazz- and organised-crime- communities frequently intersected, forced together not least by prohibition. This would not have been Waller's first encounter with the violent side of popular music. Nor is it likely that he was kept partying against his will: Waller and Capone could match one another drink for drink, and Waller had grown up in a Harlem well-known for all-night booze-and-jazz sessions.

It caught up with both of them: Waller died aged 39, and Capone disintegrated on release from prison. But, to its great credit, that was not the end for this documentary. It went on to tell those of us who - even though male, middle-aged, and overweight - are not au fait with jazz history why Waller was and is so important; and why he was not taken as seriously as he should have been.

Part of the answer to the latter is race: there was no place for the truly creative black musician at that time; so Waller instead presented himself as part minstrel and part clown, content to take film roles such as the elevator boy in the 1936 King of Burlesque. For all his faults, Capone was unusual in his support for black musicians, even if - as one commentator put it - the music he liked to hear most of all was the sound of baseball bat on skull.

"Music To Kill To." It is not likely to appear in Classic FM's range of CD anthologies any time soon; and the myth of music as a universally redemptive, altruistic, democratic activity is joyfully and ubiquitously perpetuated. Thus Something Understood (Radio 4, Sunday) took as its theme last week "Feeling groovy", and featured the jazz-band leader Django Bates's welding together of rhythmic music from the Aka pygmies of Cameroon to Charles Mingus.

I have rarely understood anything in Something Understood - although, since it goes out early in the morning and is repeated late at night, perhaps it is designed to represent the Joycean stream of consciousness of a presenter half asleep. The take-home message of this episode appears to have been "It don't mean a thing if it ain't got that swing"; but it might have been "Doo-wah, doo-wah, doo-wah, doo-wah, doo-wah. . ."