Haydn’s many folksong arrangements for the Edinburgh publisher George Thomson were a lucrative sideline of his old age. A decade earlier, though, he had turned out trio arrangements of 100 “Original Scots Songs”, apparently as an act of charity to bolster the failing London publisher William Napier. Not all the tunes were quite as “original” as the publisher implied but these “wild and expressive melodies” (Napier’s words), duly refined for the domestic market, were a sure-fire success at a time when mist-shrouded Celtic primitivism was all the rage.

These Napier arrangements are altogether less elaborate than the ones Haydn later made for Thomson. Skittering violin figuration can add a kick and a flourish to the livelier songs. But discretion rules. Haydn probably arranged the tunes without the aid of texts (or translations), which may account for some mismatches between words and music. The mellifluous arrangement of the duet “Marg’ret’s Ghost”, for instance, could hardly be less spooky. Still, many of the tunes are haunting, and more often than not Haydn’s arrangements delicately enhance their expressiveness. As in earlier instalments in this series, the Scottish pair of Lorna Anderson and Jamie MacDougall are fresh of tone and thoroughly idiomatic in expression. The Haydn Trio Eisenstadt provide expertly judged accompaniments, with the violinist making much of her opportunities for spirited commentary.

Though not quite a linguistic match for the Anderson-MacDougall axis, Wolfgang Holzmair sings with flair and – a few minor mispronunciations aside – impressive clarity of diction in folksong arrangements by Beethoven, Haydn and Haydn’s one-time pupil Ignaz Pleyel. He even essays a more than passable “Oirish” in Beethoven’s jaunty “The Pulse of an Irishman”. Although Beethoven initially complained to George Thomson that setting folksongs “gave a true artist no real pleasure”, the composer obviously warmed to his task. His trio accompaniments abound in felicities of harmony and texture, even touches of motivic development (you can never repress the symphonist in Beethoven for long). Time and again he creates preludes and epilogues that encapsulate the songs’ essence, nowhere more ravishingly than in the setting of “Faithfu’ Johnnie”. The three Pleyel arrangements, though agreeable, are much less inventive; and no one would guess from the decorous “Oh, open the door” that the girl’s lover is dying of hypothermia.

With his plangent, tenorish timbre and care for a pure legato line, Holzmair sings with unaffected sensitivity in the gentler songs. Elsewhere he “sells” the many lusty drinking songs and ballads with humour and brio, though occasionally – as in Haydn’s splenetic “My love she’s but a lassie yet” – resorting to a kind of Sprechgesang. Trio Wanderer, with plenty here to engage them, play with style, zest and evident enjoyment. The awkwardly translated French note is long on guff and gobbledegook (“our existences are a play of permanently self-reflecting mirrors”), short on helpful, accurate information.