Classical Songbook The Almeida, London

Musical marathons are a special species. Endemically taxing to the artist, of course, but no less demanding for the listener: more may rapidly become less. Almeida Opera, the virtually indistinguishable successor to the old Almeida Festival, has opted to keep some of its precursor's programming traditions, marathons in particular. But even in the indefatigable hands (and fingers) of the much-missed Yvar Mikashoff, whose marathons of many varieties set the pace, attention would drift, especially as the interior temperature of the Almeida rose inexorably on sunny summer afternoons.

The "Mary Wiegold Songbook" is an ingenious idea. Since 1988, more than 150 composers have added to its contents. Contributions range in length from near-aphorisms to full dramatic scenas. None is commissioned. For the young composer, it's a handy outlet, while, for the more senior one, a generous gift. "Songbook is an idea not a publication" - and, as an idea, it does offer an intriguing guide to "who's up to what stylistically" over a bewilderingly wide range. The majority of composers are British but the net is now spread wide and some exotic fish are swimming in.

The Composers Ensemble has provided the performing tool, and indeed relies on the Songbook as its major programming resource. The line-up is an unusual one: two clarinets (doubling as bass clarinet and swanney whistle), a viola, a cello and a double-bass. For Sunday's concert, 41 solo songs (two with vocal "re-enforcements") were selected, including 11 world premieres and eight London premieres. Three purely instrumental pieces were also thrown in.

Since the whole thing lasted four and a half hours (two 20-minute intervals gave the exercise the appearance of three concerts and the unsporting a chance to flee), Mary Wiegold was wise to get in a couple of "helpers": the soprano Adey Grummet and the mezzo Pamela Helen Stephen. She also brought in three conductors: Brad Cohen, who took the lion's share, Martyn Brabbins, who clocked up a mere three items, and Richard Armstrong, who conducted just one.

The most memorable numbers were Judith Weir's The Romance of Count Arnaldos, Kurt Schwertsik's shockingly tonal Human existence..., Howard Skempton's exquisite How Slow the Wind, Michael Finnissy's cod-chant O quam glorifica luce, John Hawkins's The Bedbug, Colin Matthews's Richard Strauss-inspired Cantata on the Death of Anthony, Simon Bainbridge's smoky A Song from Michelangelo, and Harrison Birtwistle's White and Light. Most of these can be heard on a splendid NMC disc. So why, in a space so perfectly scaled, was the experience so mixed? Not the fault of the works, I would suggest, but the mixed blessings of patronage by a performing artist whose skills are distinctly limited.

Wiegold has brought into being a vast number of works, for which only praise is due, but her vocal delivery, pinched and strained at the top, leaves much wanting. Only Pamela Helen Stephen, a generous, well-focused mezzo with plenty of panache, delivering a mere three songs (including the Matthews), made these compositional "jewels" really shine. And Adey Grummet had eyes for her score and the conductor only.

The Almeida Opera series continues to Sat. Booking: 0171-354 4404