We have John Eliot Gardiner to thank for an unconventional diptych of Czech masterpieces in the London Symphony Orchestra's current season. He had to withdraw from last night's concert - he conducts Dvořák's Cello Concerto and Suk's "Asrael" Symphony on Thursday - but his replacement, Kazushi Ono, was no second-best.

"Revelatory":  it’s one of those words which is now completely devalued through having been carelessly dropped into a thousand press releases.

Some of the greatest pieces of the string orchestra repertoire are based on pre-existing pieces: the fantasias by Tippett and Vaughan Williams, on Corelli and Tallis respectively, treat their starting material with invention and sweep, creating something new, bigger and better than their sources. But throughout Lera Auerbach’s Dialogues on Stabat Mater (after Pergolesi) last night I felt nothing other than the desire to hear the Pergolesi original, unadorned and unmeddled-with.

Changes from the artists originally advertised can bring some happy discoveries. Sir Mark Elder, though present in the audience to hear last night’s Hallé performance at the Bridgewater Hall, was still recovering from surgery and so did not conduct it, as he’d planned to when the season was announced. Instead, the Hallé Youth Orchestra’s music director (and noted choral director) Ellie Slorach took the baton for the first work in the programme – Weinberg’s Rhapsody on Moldavian Themes.

It remains some of the most terrifying music ever written. Shostakovich’s Tenth Symphony - the composer’s portrayal of the fear and anxiety felt under Stalin's regime - is a horrifyingly brutal musical portrayal of life lived under a totalitarian reign.

Dichterliebe is a song-cycle full of gaps, silences, absences. Where is the piano at the start of “Ich hab’ im Traum geweinet” when the voice enters first and so startlingly, ungrammatically alone? Where is the voice during the long piano postlude when the vocal line disappears but the singer continues to stand centre-stage? We even seem to join the cycle mid-conversation, unsure what has prompted the diffident, tentative harmonies with which it starts.

Verdi, Elgar, Janáček, John Adams - just four composers who achieved musical transcendence to religious texts as what convention would label non-believers, and so have no need of the "forgiveness" the Fátima zealots pray for their kind in James MacMillan's The Sun Danced.

You seldom expect to feel the breath of apocalypse and the terror of the grave amid the modestly rationalist architecture and passion-killer acoustics of the Royal Festival Hall.

Handel’s Brockes-Passion is a curious piece - sacred but not liturgical, and with a strong influence from opera, though it is a concert work. Solo voices predominate, and the singers assembled at Wigmore Hall were mostly fine.

The conductor Thomas Søndergård turned 50 on Friday.