Myaskovsky had yet to learn where he would be assigned, knowing only that his departure was imminent. He hoped to be sent to Moscow, but on 4 August received instructions to report three days later to an army base in Borovichi, a town situated 210 miles southeast of St Petersburg. He spent his last few days of freedom finalising the fair copy of the Third Symphony. As usual after completing a major project, he was immediately wracked with agonies of self-doubt despite his friends’ enthusiastic responses when he played the score to them – Krïzhanovsky went so far as to invoke comparisons with Tchaikovsky's Pathétique.

Their enthusiasm was merited: in every respect, Symphony no. 3 in A minor, op. 15, represents a notable advance on its predecessors. It not only surpasses them in technical sophistication and expressive force but is also more novel in conception, as its design constitutes a radical rethinking of traditional formal approaches. The symphony is cast in two movements – a predominantly quick sonata-allegro lasting about twenty minutes followed by a rondo which is also in a fast tempo but culminates in a slow epilogue with the character of a funeral march. Two-movement symphonies are surprisingly uncommon, principally, one suspects, because of the inherent problem of attaining overall unity: the chief difficulty is to ensure that the second movement will provide a persuasive ending to the work as a whole and not leave an impression of incompleteness. To accomplish this, it must convey a sense that it brings unfinished business from the first movement to a satisfactory conclusion. Furthermore, the problem of integrating slow and fast music in a two-movement symphony is particularly acute. Myaskovsky's solution to these challenges is as original as it is ingenious. As in his previous symphonies, the second subject group in his turbulent first movement is much slower in tempo. When it returns in the recapitulation, one of its component ideas is subjected to further development in an ethereal slow coda that follows without a break; and although the movement ends in the tonic major, its stability is precarious, undermined up to the last by excursions to remote harmonic regions and a strangely indeterminate final cadence.