INCIDENTAL exercise is a phrase which has entered popular parlance in Australia to describes exercise built into everyday routines, such as walking up and down stairs.

For musicians, everyday routines can involve lifting enormous amplifiers, PA speakers and drumtackle bags. Thanks to this particular incidental exercise, local jazz hero Karl Mullen has succumbed to the occupational hazard of an injured back. As a result, he has been confined to the house.

Last Wednesday's session at the Black Swan, Peasholme Green, was turned over to a Karl benefit night, in a bid to halt his rapid acceleration towards the breadline. Friends too numerous to mention played, held a raffle and an auction. The generosity of all involved is testament to the high regard they have for Karl, pictured, and the proceeds will ensure he has shelter from the winter winds and a glass of nourishing crotchet juice now and again. Get well soon, Karl.

Bass player Paul Baxter is one of the organisers of jazz at the Black Swan. He tells me that the new policy of booking a guest musician occasionally will continue next Wednesday with the appearance of Frank Brooker. Frank is a great regional favourite on clarinet, saxophone and the occasional vocal and an early arrival is recommended at the tiny venue.

There is an exciting weekend ahead, featuring some solid jazz names. Tonight, Wakefield Jazz presents the Frank Griffith Nonet.

American-born Frank is head of musical performance at Brunel University and was a guest with the Leeds College big band last year. He worked in New York for 15 years with the big bands of Buddy Rich and Toshiko Akiyoshi, among others, and he writes beautifully crafted scores for the Nonet, which sounds like a mini big band. Henry Lowther (trumpet) and Paul Clarvis (drums) feature in the nine-piece, details from 01977 680542.

Tomorrow night's big news is jazz at Howden Live, with the Geoff Mason/Roland Lacey Quintet. This London-based, Blue Note-style band is influenced by Horace Silver, JJ Johnson and Clifford Brown, and is driven along by ex-York resident Adrian Macintosh.

Adrian is taking a busman's holiday from his customary drum chair with the Humphrey Lyttelton Band, and this will be a rare opportunity to hear Adrian and the band outside of London.

Howden Live is at the Shire Hall, Market Place, details from 01430 431535. Incidentally, there will be a jazz singing and improvisation workshop, led by Louise Gibbs, at Howden on Saturday, February 23, from 2pm to 5.30pm. The maximum number for the class will be 15, and tickets costing £30 can be booked from Mike Pinfold by phoning 01430 422059.

The rival attraction tomorrow night will be at Jazz In The Spa, when John Sillito's Select Six will bring their New Orleans/Harlem music to Boston Spa. The venue is the Trustees Hall, High Street (01937 842544).

Sunday lunchtime jazz in York is a two-horse race, with Bejazzled at the Revolution Bar, Coney Street (01904 676054) and Rob Lavers Quartet at Kennedys Cafe Bar, Little Stonegate (01904 620222).

The Bejazzled duo of Don Lodge and Tim New play gentle, chilled jazz standards, while Rob's band cover similar ground, with one or two originals and added bass and drums. The problem is that both operate from 1 pm to 4pm, so you have to make your choice, or jog the five minutes or so from one to the other.

On Thursday, Bejazzled becomes a four-piece and moves to the Old White Swan, Goodramgate (01904 540911).

Saxophonist/vocalist Laura Fowles is always welcome at Scarborough Jazz and she was a big hit at last year's Scarborough Jazz Festival.

Something of a globe-trotter, Leeds-based Laura is likely to have flown in from Ibiza or Germany, where she plays saxophone with the high-flying Fresh DJ organisation. Oh, and she played support on the Take That Beautiful World tour. Details of Scarborough Jazz from Marian and Mike on 01723 379818. Laura has two websites, www.thelovelylaura.co.uk (disco stuff) and www.laurafowles.com (jazz stuff).