Berio's Sinfonia is one of the musical icons of the 1960s: a multi-layered fusion of words and music, full of glistening sounds supporting a web of cultural allusions. Any Berio festival of real weight has to include it, and so the celebration on the South Bank ended with the score performed by the vocal group Synergy and the BBC Symphony Orchestra conducted by Jukka-Pekka Saraste.

Performances of such a celebrated piece aren't as common as they might - the orchestra required is vast, and the vocal techniques needed specialised - and, as this account showed, it does not play itself. From where I was sitting, the balance between the amplified voices and the orchestra was problematic, and in the famous central movement, a stream of musical consciousness built upon the scherzo from Mahler's Second Symphony, the comments and quotations from Beckett, Joyce and Lévi-Strauss were all but submerged.

It came at the end of a three-part Berio programme that included Andrea Lucchesini's account of the 2001 Piano Sonata, less compelling that it might have been and distinctly over-extended, as was Ekphrasis (Continuo II) from 1996, a typical expansion of an earlier work, which generates some luminous textures but nothing more memorable. Saraste presented it efficiently, though, and the performance was better than the BBCSO's shaky attempt on Berio's completion of the final contrapunctus from Bach's Art of Fugue.

The middle weekend of this series had provided performances of all of the solo sequenzas, as well as two concerts from the London Sinfonietta. One explored Berio's devotion to folk traditions, in a performance of his Folksongs cycle alongside music from Sardinia, Armenia and Kurdistan. The other, in which the Sinfonietta was joined by the Royal Academy of Music's Manson Ensemble and conducted by Zsolt Nagy, returned to his persistent preoccupation with voices and texts. The settings of old testament texts in Ofanim may be problematic - too generalised, their use of electronics seems tame now - but the 1965 Dante homage Laborintus II is one of his finest non-operatic achievements, and still wears well, weaving narration, choral settings and fierce instrumental commentary into a magical unity, and presenting Berio's genius at its most powerful.

· Omaggio ends tomorrow at the Royal Academy of Music, London NW1. Box office: 0870 264 2244.