Sofia Gubaidulina (left) with Elena Firsova
The late Sofia Gubaidulina left Prolog unfinished if with detailed notes as to how she intended to complete it, which has been undertaken by Elena Firsova. Premiered two evenings prior to this performance, Prolog is a compelling piece of mystery, intensity and incident, entering into strange expressive regions, sympathetically and skillfully made whole by Firsova (twenty minutes growing from Gubaidulina’s drafted six), and given an equally sympathetic and skillful account here.
Nelsons’s conducting of Mahler Seven peers into its potential with flexibility, expansive in design, imagery in sound, presenting the five movements unabashed, detail exposed, played heroically by the BSO, ending with a Festive Finale that is also ambiguous, surely Mahler’s intention. Well-worth a listen, but I don’t know how long CRB’s archived recordings stay available.
https://www.classicalwcrb.org/