Claire Martin calls her new CD "my life in 64 minutes". Launching Every Now and Then at the Dean Street Pizza Express this week, this most effortlessly rhythmic and intuitively musical of orthodox UK jazz singers thus appropriately indicated more than a usual willingness to reveal what she's really about.

Martin has been a superb technician for years, with an improvisor's relish for transforming her materials, and an instrumentalist's melodic dexterity. She has also been a shrewd judge of overlooked songs - and if there's ever been a downside to her work, it has only figured in a kind of vivacious guardedness. A relaxed, funny and charismatic occupant of a spotlight's beam, Martin sometimes nevertheless seems to protect her deepest feelings - unlike her most idiosyncratic model Betty Carter, who always sounded like a vibrating piano wire.

But in the company of an excellent ensemble comprising some of the best accompanists of singers on the UK circuit (Gareth Williams on piano, Geoff Gascoyne on bass and Clark Tracey on drums) Martin is giving the songs that have been a soundtrack to her life all the eloquent commitment she knows how. She eagerly dug into the groove under a Joni Mitchell song, her swooping lines and exclamatory, drumlike sounds tugged and nudged by Clark Tracey's Art Blakey-like snare-drum rolls, and the planted, contrastingly solemn-sounding chording under the song (recalling Herbie Hancock's Maiden Voyage) was exuberantly swept out into the late Gene Harris's funk-piano territory by the inventive Gareth Williams.

Claire Martin's ducking and diving fluency of line at fast tempos was unperturbed by Al Jarreau's careering Better Than Anything, and as this flyer went on the singer sounded ever more confident to surf on the outer limits of its envelope. Martin's Betty Carter connection was recalled on that departed star's staccato classic Tight, which veered melodically across the full width of the singer's range and featured a fleet bass break from Geoff Gascoyne. The road-weary musicians' song Another Night, despite its rather on-the-nose lyrics, brought a heartfelt and affecting interpretation from Martin, and Any Place I Hang My Hat Is Home unerringly steered its way over a mantra-like piano riff and Tracey's ringing cymbals.

· Claire Martin is at the Pizza Express until Saturday, and Every Now and Then is out on Linn Records.