The complete Mozart multipiano concertos is even more complete than the composer might have anticipated. In between pristine accounts of the concertos for two and three pianos, the MultiPiano Ensemble and English Chamber Orchestra give the premiere recording of an extended sketch, idiomatically completed and orchestrated by Tomer Lev. The artistic value of the fragment—which dates from around 1781, the beginning of Mozart's life as a freelance composer in Vienna—is beyond question, and the opportunity to hear it makes April's Record of the Month a Mozartian treat not to be missed.

The ghosts of pre-Reformation Scotland are vividly conjured in Music for the King of Scots, as The Binchois Consort and Andrew Kirkman celebrate Mass for James IV. Linlithgow Palace may now be derelict, but here its Chapel Royal once again resounds to music over the course of the liturgical day, as it might have been heard in the early sixteenth century. And with Sacred choral music by Cecilia McDowall we celebrate the seventieth birthday of one of this country's most distinguished contemporary composers. McDowall is famed especially for her choral writing—equally rewarding for listeners and performers alike—and this collection of works from the last decade enjoys outstanding accounts from Stephen Layton and Trinity College Choir Cambridge.

An occasional series dedicated to choice selections of our all-time favourite recordings—ones you might possibly have missed? This time: The Golden Age of English Polyphony from The Sixteen (‘English choral music at its finest’—The Observer), Kaleidoscope from Marc-André Hamelin (‘simply sensational’—The Sunday Times), and the Pierné Piano Quintet from Piers Lane and the Goldner String Quartet (‘it would be hard to imagine a more persuasive or compelling performance’—Gramophone). If you don't know them already, a track from each is included on our monthly sampler which is free to download.

St John's College Choir Cambridge has recorded a second volume in its Magnificat mini-series on Signum. Conductor Andrew Nethsingha builds a programme of favourite, and varied, canticles spanning much of the twentieth century, and includes the first recording of a new set commissioned by the college from Julian Anderson.

On their own LSO Live label, the London Symphony Orchestra presents new recordings of Vaughan Williams Symphonies Nos 4 & 6. As conductor Antonio Pappano notes, these recordings were captured live on dates of particular national tension, something which infused atmosphere and players with almost preternatural determination to excel.

New from Signum Classics this month we have the magisterial final instalment in Thomas Adès' Beethoven Symphonies cycle. These performances with the Britten Sinfonia are compelling, the pealing voices in the finale of No 9 every bit as the composer must have imagined them.

Countertenor William Towers has joined forces with Christopher Monks and his enterprising Armonico Consort to record Handelian Pyrotechnics: eleven of Handel's finest arias, many originally composed for the great 'Senesino', in assured performances made with the experience of many stage productions.

Rediscovered – British Clarinet Concertos, on the Cala Signum imprint, is a wonderful exploration of the clarinet-and-orchestra byways of England in the 1930s and 40s: a collaboration between Peter Cigleris and the BBC National Orchestra of Wales, the album presents four revelatory works by four little-known composers. Ben Palmer conducts. On the main Signum label we have Spira, spera, a programme of Bach piano transcriptions—including rare outings for two monumental creations by Theodor Szántó—performed by Emmanuel Despax.

New on the King's Cambridge label we have Proud Songsters – English solo song. Nine distinguished singers—Michael Chance, James Gilchrist and Gerald Finley among them, and all former members of the college's famous choir—share the honours, with Simon Lepper their indefatigable journeyman.

Rather different fruits of the choral tradition can be found in Percussion Concertos by HK Gruber, the composer a one-time member of the Vienna Boys Choir, if now rather more regarded as a musical anarchist. Colin Currie hits things (his own label hosting the recording), while Juanjo Mena and John Storgårds share attempts to marshal the BBC Philharmonic.