The programme alone whets the appetite. The Israeli soprano Chen Reiss and Richard Egarr have concocted an offbeat selection of Beethoven arias that interleaves a smattering of familiar items with real rarities. Only the most fervent Beethoven completist is likely to know the two Italian scenas Primo amore and No, non turbarti, the latter written while Beethoven was studying Italian word-setting with Salieri; or the jaunty, Papageno-ish ‘Soll ein Schuh nicht drücken’, written to be performed in a Singspiel by Ignaz Umlauf; or the guileless song with harp, like an early Schubert Lied, which Beethoven composed for the play Leonore Prohaska. The young Beethoven can be prolix, not always idiomatic in his writing for the voice, most obviously in the two earliest works, Primo amore and the bravura aria with flute and cello ‘Fliesse, Wonnezähre’ from the ‘Leopold’ Cantata. Yet while the spirit of Mozart is ominipresent, these arias abound in colour, inventiveness and – not the first epithet that springs to mind with Beethoven – charm.

Abetted by eloquent solos from the (unnamed) AAM flautist and cellist, Chen Reiss sets out her stall in a confident, outgoing performance of ‘Fliesse, Wonnezähre’, soaring effortlessly above the stave and sporting a true trill. Here and elsewhere, her diction, both German and Italian, can be cloudy, with insufficiently incisive consonants. I noticed this particularly in the stormy recitatives that open Ah! perfido and No, non turbarti – a far more concise and effective piece of writing than the earlier Primo amore.

This reservation aside, Reiss uses her bright, even-toned soprano with taste and imagination, spins a true legato line and characterises thoughtfully. If the cobbler’s wife’s demotic ‘Soll ein Schuh’ could have more of a roguish twinkle, she is delightful in Klärchen’s two songs from Egmont, the one swaggering (with splendidly brazen sounds from the AAM), the other tenderly quizzical. The romance with harp from Leonore Prohaska has just the right ingenuous grace. And, diction apart, Reiss musters an apt touch of the grand manner in a dramatically intense Ah! perfido. There’s an engaging note from Reiss herself and an informative one from Andrew Stewart, though they can’t seem to agree about the identity of Beethoven’s earliest ‘immortal beloved’ that gives this enterprising disc its title.