Bathed in the sunshine of Bach

Mozart may be the world's most popular composer, but the most influential one remains JS Bach. In celebrating the 250th anniversary of his death, the BBC in this year's Proms season may not have set out to prove the point, but already the case is looking beyond reasonable doubt. The first two concerts of the series showed the durability of Bach's work, whether presented as Gothic travesty or unvarnished original. Proms 3 and 4 proceeded to show its past and present ubiquity, by way of two unusual premieres.

Mozart may be the world's most popular composer, but the most influential one remains JS Bach. In celebrating the 250th anniversary of his death, the BBC in this year's Proms season may not have set out to prove the point, but already the case is looking beyond reasonable doubt. The first two concerts of the series showed the durability of Bach's work, whether presented as Gothic travesty or unvarnished original. Proms 3 and 4 proceeded to show its past and present ubiquity, by way of two unusual premieres.

The first was from Felix Mendelssohn: his oratorio St Paul, which dates from 1836 but is new to the Royal Albert Hall. It was performed with generous dedication on Sunday evening by a mighty array of voices, including those of the Houston Symphony Chorus (making their Proms debut), the BBC National Chorus of Wales, and the London Symphony Chorus, with Richard Hickox conducting the BBC National Orchestra of Wales.

From the opening Lutheran choral of "Wachet auf" resounding through the fugal overture, this is music steeped in Bachian style and spirit, a fact of which the composer, who in 1829 had revived the long-forgotten St Matthew Passion, was justly proud. Being by Mendelssohn, the music also contains marvellous woodwind writing, for flutes, clarinets and horn - for example, in the soprano Susan Gritton's part-one "Jerusalem" aria. In the art of transition, too, there were masterly strokes, and the recitatives were brim-full of fresh invention.

Though Monday's early evening Prom seemed to come from another world, it was none the less still bathed in the sunshine of Bach. That happens to be the title of a piece by Julian Yu, whose BBC-commissioned Not a Stream but an Ocean (a Beethoven quotation and a pun on Bach's name in German) used the Baroque passacaglia form to pay tribute to the German master. Its measured, conservative surface (the final medley of favourite fugal themes sounded like dyslexic Reger) led from the carefully suppressed tension of the opening to a variety of episodes that would repay further hearing.

After the interval, the conductor George Benjamin's Palimpsest swiftly traversed a variety of moods and attitudes, assuming under its composer's baton a softer, more intriguing profile than under that of its dedicatee, Pierre Boulez. Elsewhere, music close to Benjamin's heart brought forth of his best: Messiaen's Oiseaux exotiques, with the pianist Pierre-Laurent Aimard, and Debussy's Prélude à l'aprés-midi d'un faune as drowsy yet detailed as "The Princesses' Round Dance" from Stravinsky's suite from The Firebird, which ended the evening.

Music by British composers not unnaturally dominated the late-night Prom, given by the choir of King's College, Cambridge, and exploring this year's other theme of music inspired by man's relationship with God. To the timeless chant of Jonathan Harvey's "I Love the Lord", James MacMillan's "A New Song" brought a more sombre note.

Bach ended the evening: "Lobet den Hern", a strong reminder that in the music of this, of all composers, not once is there a sense of the merely adequate.