Mr Tulliver in George Eliot's1860 novel The Mill on the Floss famously warned his daughter against judging books by their covers and the same advice could be echoed with CD packaging.
Sacred Duets, a charming new Sony release, is guaranteed to capture hearts within a few phrases of its opening track; that is, unless you're frightened off by a booklet essay dauntingly headed, "Innovation and Tradition in the Italian Oratorio 1670-1740."
As it happens, what sounds like the title of a dry doctoral thesis introduces six welcoming pages of fascinating background. The only possible improvement would have been printing it in uncluttered black on white, with a slightly larger typeface.
It's here that we meet those Italian composers who found their way to Rome and contributed to one of the most expressive of all Baroque musical forms.
It's an impressive lineage, from Alessandro Scarlatti to Nicolo Porpora who, in my youth, was unjustly relegated to the footnotes of history as Haydn's teacher.
Both men contribute to the disc's seven duets; Porpora with an elegantly stylised dialogue between Justice and Peace, one of the collection's jewels, both musically and in performance.
Here and elsewhere, the voices of Catalan soprano Nuria Rial and German countertenor Valer Sabadus blend with a rare lyrical beauty, shaded by shiveringly effective ornamentation.
The opera house is never far away in this music. In a Bononcini aria portraying the conversion of Mary Magdalene, Rial sings with grace and vitality on the anguish of a defenceless heart, warding off enemies. Sabadus' brilliant flurries of fury in an aria by Antonio Caldara portray a vengeful pagan tyrant with fire in his coloratura.
Kammerorchester Basel, led by violinist Julia Schroder, is rewarded for its immaculate accompaniment duties with the chance to deliver a spirited Torelli concerto grosso. The flamboyance of the playing sometimes verges on the operatic and, with no religious connections explained in the booklet, it stands as a delightfully secular entr'acte.
What: Sacred Duets (Sony)
Verdict: The perils of judging a CD by its booklet
Reviewed by William Dart