Sea Interludes, Op 33a, is a suite of about 17 minutes' duration, comprising the first, third, fifth and second interludes from the opera, with the titles "Dawn", "Sunday Morning", "Moonlight" and "Storm". The fourth interlude, a passacaglia, has been published separately as Op 33b, and is sometimes appended to the Four Sea Interludes in concert and recordings. Britten conducted the London Philharmonic Orchestra in the first performance of the suite at the Cheltenham Festival, a week after the opera's premiere; the London premiere was at the Proms, in August 1945, and the five interludes were conducted by Sir Thomas Beecham in October 1945. Critical reception First productions In The Observer, William Glock rated the first act less convincing than the other two, but found the opera as a whole "a most thrilling work", displaying Britten's "genius". The Manchester Guardian'''s critic, William McNaught, considered the music "full of vivid suggestion and action, sometimes rising to a kind of white-hot poetry", but thought the libretto insufficiently "operatic" – "overloaded with scrappy and not always telling incident". The Scotsman's critic took a different view, calling the work "that rare thing – a piece of perfect collaboration between librettist and composer". The reviewer in The Times found the use of a single spoken line for Balstrode at a key point intrusive in an otherwise through-composed score, but praised Britten's "effortless originality" and "orchestral music of diabolical cunning". After the American premiere, the critic Douglas Watt opened his review "Peter Grimes has greatness", and called the work "an opera for our time, brilliantly conceived and executed", with the "breathtaking pleasure" of the music matched by "the strong and lovely libretto", though he predicted that if an impresario succeeded in staging the piece on Broadway "it will be met with much intolerance and displeasure by audiences unprepared for its surprising magnificences". In The Boston Globe, Cyrus Durgin praised the young Bernstein for bringing out "the drive and dissonance of an opera which is far from 'tuneful' in the conventional sense" and rated the work "a step forward for opera in this country, and anywhere for that matter". Later assessmentsGrove's Dictionary of Music and Musicians describes Peter Grimes as "a powerful allegory of homosexual oppression", and The New York Times has called it one of "the true operatic masterpieces of the 20th century"; the composer's own contemporary (1948) summation of the work was "a subject very close