Educated at Christ's Hospital and the Royal College of Music, Lambert was a prodigy, writing orchestral works from the age of 13, and at 20 received a commission to write a ballet for Serge Diaghilev's Ballets Russes (Romeo and Juliet). For a few years he enjoyed a meteoric celebrity, culminating in the broadcast and concert performances of his Rio Grande for piano solo, chorus and orchestra. A recording survives with Hamilton Harty as the soloist and the Hallé Orchestra conducted by the composer.
During the 1930s his career as a conductor took off with his appointment with the Vic-Wells ballet (later the Royal Ballet), but his career as a composer stagnated, and after the disappointing reception of his major choral work Summer's Last Will and Testament which proved unfashionable in the mood following the death of the King (George V) he considered he had failed as a composer, and completed only two major works in the remaining sixteen years of his life. Instead he concentrated on conducting, and appeared at Covent Garden and in BBC broadcasts, and accompanied the ballet in European and American tours.
The war took its toll of his vitality and creativity, and his health declined with the development of diabetes which remained untreated for years owing to his fear of doctors, stemming from childhood.
Lambert was famous in his day as a raconteur and, unusually for an Englishman, as an expert on many different arts, and on modern European culture. He was also one of the first "serious" composers to understand fully the importance of jazz and popular culture in the music of his time. He was at the centre of a brilliant literary and intellectual circle including Michael Ayrton, Sacheverell Sitwell and Anthony Powell, and despite Powell's denial, he is clearly the prototype of the character George Moreland in Powell's A Dance to the Music of Time.
As a conductor he had a prescient appreciation of Liszt, Chabrier, Waldteufel and romantic Russian composers, and made fine recordings of some of their works. Tragically, it was only when his health was declining that his career had a chance to flourish with the development of the BBC Third Programme and the Philharmonia Orchestra, having struggled for many years to extract vital performances from second-rate ensembles.