You have a few good choices in this repertoire: Tonu Kaljuste and the Swedish Radio Choir’s speedy, dynamic, yet brightly recorded version on Virgin; a more vocally idiomatic rendition by the St. Petersburg Chamber Choir on Philips whose very resonant acoustic balances significantly toward the soprano voices; the Voronezh Chamber Choir’s excellent (but again very resonant) recording on Globe that includes an occasional introductory solo chant and whose interpretations regarding dynamics, syllabic accents, and tempo markedly contrast to all the others; and, my favorite, Robert Shaw and his hand-picked Festival Singers on Telarc, who deliver the overall best-performed–beautifully sung, emotionally powerful, notably slower–and superbly recorded version.
Which brings us to the current reading, by another “non-idiomatic” yet exceptional (German) choir, whose rendition seeks to set a more liturgical context than the other recordings with insertions of chants by a “lector” before six of the choral sections. For me, these solo chants, by Bulgarian bass Lew Maidatschewski, are interesting but after first hearing become unwelcome interruptions. Yes, they can be skipped with a touch of the remote button, or programmed out–they’re on separate tracks–if you know how to do that sort of thing, but suffice it to say that for most listeners these bits of “authenticism” will add nothing to Rachmaninov’s score. Aside from that, these are absolutely first-rate performances–the singing and warmly expressive interpretations easily rival those of Shaw and his Festival Singers, and the sound is near-ideal. If you don’t mind the above-mentioned additions, this beautiful performance by the MDR Rundfunkchor Leipzig will satisfy your library’s need for at least one Rachmaninov Vespers; if you just want the uninterrupted choral movements in all their glory, go for the Shaw.