Rachmaninov wrote Vocalise for voice and piano, not setting a text to it, unlike the other songs in the Op. 34 set. It immediately became popular, and the composer fashioned several transcriptions of the work, including one for piano and another for orchestra. In a sense, the orchestral version is the better of these two, because its string-dominated scoring more effectively captures the sustained sonorities of the original. That said, Rachmaninov, a brilliant composer of piano music and virtuoso pianist himself, compensated for his instrument's non-sostenuto tone by the scaling down textures and adding pedal runs and other coloristic effects.
Heard in any of the versions, the main theme is lovely, but here its long-breathed, soaring beauty and ecstatic sense of melancholy come across with a more straightforward and even simple expressive manner. Not that the piano sonorities are scrawny or the textures skeletal and inappropriate: indeed, the music takes well to the tender, more intimate dressing Rachmaninov deftly provides here. In the first half the music remains gentle and flowing, but around the midpoint turns intense and more passionate, developing a strong sense of yearning, almost of anger. The main theme returns in much the same intimate mood it appeared in at the opening and closes out this lovely work.