John Longstaff was born in Lancashire, read music at Girton College, Cambridge and studied conducting at the Guildhall School of Music and Drama, and also with George Hurst. In 1988 he was awarded 2nd prize in the Leeds Conductors' Competition and in 1991 was a finalist in the first ever Donatella Flick Conductors Competition. He was appointed Musical Director of the Sheffield Symphony Orchestra in 1993, becoming Artistic Director in September 2001-2011. He still conducts the SSO as a guest. He has held full time posts as rehearsal pianist and conductor at the Opera House in Kiel, Germany, and with Northern Ballet Theatre, in addition to guest engagements for Opera North, the D'Oyly Carte Opera Company and Opera Lirica. He is currently Director of Music at St. Peter’s Church, Harrogate.
As a composer and arranger he has been responsible for many ballet scores - in Kielhe composed the music for the full-length ballet Dorian (after Oscar Wilde) and he revised the original score of La Sylphide for the Theater der Stadt Koblenz, a score which was also produced in Lüneburg. He has made many reduced orchestrations for Northern Ballet Theatre, including Romeo and Juliet (Prokofiev), Swan Lake(Tchaikovsky), Don Quixote (Minkus), and Carmen (Bizet). His arrangement of music by Elgar for Great Expectations was recorded by NPC records, and was chosen by a critic in Gramophone magazine as his top recommendation of new CDs reviewed in the year 2000. Following the appointment of David Nixon as Artistic Director of Northern Ballet Theatre John has arranged the scores for the hugely successful ballet version of Madame Butterfly (Puccini), an evening of choreography to the music of Gershwin entitled I Got Rhythm, a selection of impressionist French music forBeauty and the Beast, music by Mendelssohn and Brahms for a production of A Midsummer Night’s Dream in September 2003, and revised the score of Swan Lakefor a new production in February 2004. His score for The Three Musketeers to music by Malcolm Arnold was first performed in September 2006 and was issued on CD on the Quartz label last year. In September 2007 he completed a reduced orchestration ofThe Nutcracker (Tchaikovsky) which Northern Ballet Theatre has successfully toured throughout the UK. In 2011 he assisted Claude-Michel Schönberg with the editing, orchestrating and recording of his new ballet score Cleopatra. Other composers he has assisted include Thea Musgrave, Michael Nyman, Philip Feeney, Kerry Muzzey, Gary Yershon and Sally Beamish. He has also composed and arranged the music for several children's ballets; most notably composing the score for Goldilocks and the Three Bears, which was toured nationwide in 2017 and shown on BBC CBeebies.
In the realm of opera, he has made acclaimed chamber orchestrations of Tchaikovsky's Eugene Onegin (for Clonter Opera), and of Humperdinck's Hansel and Gretel for an Opera North nationwide outreach project, which was revived in Autumn 2007. His recent performing edition of Monteverdi’s The Coronation of Poppaea was staged with great success at the Leeds College of Music in April 2006. In 2002 he edited Handel's oratorio Judas Maccabaeus in the orchestration attributed to Mozart which was recently discovered in Halifax and subsequently televised on BBC4; this edition was also performed in Halle and Leipzig in June 2004, and in London in March 2006.