Variationen über Volkslieder für Klavier und Flöte (Violine) ad lib. op. 105 und 107

Beethoven had nothing against composing for money – with delightful results! On a commission from the Scottish folksong collector George Thompson he wrote no fewer than sixteen sets of variations for piano on traditional European folk tunes. Then, at the publisher’s request, he gave these fairly difficult variations a simple but charming ad libitum flute part which, with minor alterations, can also be played on a violin.?