Arvo Pärt Total Immersion, Barbican

How incredibly heartening that this latest edition of the BBC Symphony Orchestra's Total Immersion, focusing on the music of the contemporary Estonian composer, Arvo Pärt, sold out days in advance.

Including an introduction to Pärt's music by the BBC Radio 3 presenter Sara Mohr-Pietsch, Dorian Supin's documentary film about the composer, 24 Preludes for a Fugue, a freestage event by the BBC SO Family Orchestra performing a new work inspired by Pärt's music, and three concerts, Saturday's day-long exploration provided an embarrassment of riches.

The BBC Radio 3 producer who introduced the second of the day's three concerts (featuring the BBC Singers) made an especially astute observation about Pärt's music: “Simple on the page, but taxing to sing”. Unveiled in 1976 following his intensive study of early music, the basic unit of Pärt's 'tintinnabuli' style (tintinnabulum literally means 'small bell') consists of a stepwise melodic line accompanied by a triadic harmony. Scales and arpeggios - it sounds like child's play. But no. The fact that the music is so exposed, coupled with the constant sounding of the triad, means that the tiniest infidelity of pitch is disproportionately deleterious to the overall effect. Pärt's music really is unforgiving in that respect. The clear sounding, or ringing, of both the melodic and triadic voice (and the balance between them) is similarly key.

Performed by the Guildhall Consort and musicians from the Guildhall School of Music and Drama, it was fitting that the first music we heard in the opening afternoon concert was Pärt's Magnificat, one of the composer's most beloved choral works. Heard in the generous acoustic of St Giles' Cripplegate, whose famous parishioners have included William Shakespeare, Edward Alleyn and John Bunyan, this was beautifully balanced, with the choir - conducted by Eamonn Dougan – achieving a genuine pianissimo at the magical return to the hymn's opening line.

If the choir's technical command, flawless pitch and crystal clear articulation was impressive, it was their sensitivity to the text that took the breath away

Two brief instrumental pieces highlighted the inherent difficulties of playing Pärt's music. In Erdem Misirlioğlu's performance of the solo piano miniature Für Alina, the strict note-against-note counterpoint was broken when the triadic pitch at the end of one of the phrases failed to ring properly. Joined by violinist Pablo Hernan, Spiegel im Spiegel was taken just a shade too fast. The sense was less one of the numinous, more of someone having a train to catch. The soprano Jenavieve Moore was outstanding in the chamber work Stabat mater, sustaining her long notes with remarkably sure intonation and control. In keeping with its air of lamentation, the work's many silences were filled with the sound of rain beating down on the church's roof (the rain was incessant).

Featuring the BBC Singers (pictured right) under their joint Principal Guest Conductor, Paul Brough, the 6pm concert (once again in St Giles' Cripplegate) presented Pärt interpretation at its best. If the choir's technical command, flawless pitch and crystal clear articulation was impressive, it was their sensitivity to the text that took the breath away. Unfailingly beautiful in tone - the resonant basses in the second movement, 'O Adonai', were terrific - their performance of the Seven Magnificat Antiphons was one of supreme focus. Pärt's first setting in English, The Beatitudes,  was even better, with the choir delicately articulating the work's gradual harmonic ascent. Iain Farrington, who earlier gave a rapt performance of Trivium, provided the excellent organ accompaniment. In all of the works – Summa, Missa sillabica, ...which was the son of..., the choir gave a demonstration lesson in singing through the line, always providing a sense of forward momentum even at the slowest of tempos.

And so to the evening concert, a mouth-watering programme that included two symphonies, a double violin concerto, a Mass and an orchestral vignette. Conducted by fellow Estonian, Tõnu Kaljuste (pictured below), the BBC Symphony Orchestra negotiated the crunching string clusters and pounding ostinatos of Symphony No. 1 with aplomb. Following Pärt's singular tribute to the Eiffel Tower, Silhouette, the orchestra gave a most persuasive performance of the transitional Symphony No. 3. The more you hear this work – with its overt references to the tropes of medieval and renaissance music - the more you perceive the simple, two-voice unit of the tintinnabuli style screaming to be let out.

In the second half, the BBC SO strings were joined by the BBC Symphony Chorus for a nuanced reading of the Berliner Messe, in which the profound textural clearing of the Agnus Dei - and the sudden, heart-stopping shift to the major mode at the close - was movingly realised. The silence that greeted its conclusion was immediately broken when some buffoon's mobile phone went off. Can we not turn the things off for the duration of the concert? Please.

To conclude, one of the cornerstones of the tintinnabuli style: the double violin concerto Tabula rasa. Soloists Alina Ibragimova and Barnabás Kelemen gave one of the most energised and exciting performances of the first movement ('Ludus') I can recall. At times stamping on the floor for emphasis, crouching down like animals about to pounce and with bows flying in perfect sync, so locked together were Ibragimova and Kelemen in the busy, Vivaldi-like figurations that you couldn't blow smoke between them.

More than any other piece heard during a remarkable day, it was the expanding melodic arcs of the second movement, 'Silentium', that best captured the artistic credo of ECM, the label that introduced Pärt and Tabula rasa to the world with the launch of its New Series imprint in 1984: “The most beautiful sound next to silence”.

The three concerts will be broadcast this week on BBC Radio 3's 'Afternoon on 3' at 2pm (today, Wednesday and Friday respectively).

Watch an excerpt from 24 Preludes for a Fugue: