Lost in music

There's nothing like sticking to a winning formula. After its summertime success with Dorothy Fields Forever, the redoubtable King's Head now presents a second "lyrics and life" piece, taking as its subject another great American songwriter, Johnny Mercer.

Mercer famously wrote more than 1,000 songs in his 67 years, of which Alvin Rakoff 's production touches on an impressive 38.

The "hayseed" from Savannah, Georgia, founded the legendary Capitol Records, collaborated with the likes of Harold Arlen and wrote numbers that were recorded by Frank Sinatra and Ella Fitzgerald. All this, however, is barely touched on by Rakoff 's script; instead he concentrates almost exclusively on Mercer's troubled, yet not desperately scintillating, relationship with his wife Ginger.

Throughout, bare biographical facts - sometimes hilariously turned into dialogue, such as when Ginger recounts to Mercer his lifetime achievements, facts of which he is surely already aware - give little sense of the man behind the words. What made Mercer capable of penning the emotional highs of Jeepers Creepers or lows of One for My Baby remains a mystery.

The four-strong cast trip energetically through the numbers, shining particularly when they get to sing and dance as a quartet. Accentuate the Positive sees them kicking up a storm in the pews of a Baptist church; Goody Goody is another ensemble highlight. Andrew Halliday makes a suave, yet frustratingly opaque, Mercer, but the real star turn is from Alexandra Jay.

Shot to fame as the Eliza Doolittle who did rather a lot during Martine McCutcheon's many absences from My Fair Lady, Jay here confirms her status as a future great of musical theatre. Her sweet voice and nimble legs will take her far - even to her 20th birthday, which she celebrates during the show's run.

Although Too Marvellous doesn't quite reproduce the sparkle of Dorothy Fields Forever, it shares with its predecessor one particularly irritating trait. In the closing 14-song medley, some of Mercer's best numbers - Moon River, Days of Wine and Roses - are given the briefest of airings, the treatment meted out to a fair few of the creme de la Fields. If we're not going to find out about the inner workings of the man's life, at least let's hear his greatest hits in full.

Until 2 February. Information: 020 7226 1916.