I've read that the lengthy hiatus between the year of Four Pieces' completion and their actual orchestration coincided with Bartok's resigned feeling that the composition was unlikely ever to be performed. Yet, it's one of my favourites, with a uniquely Bartokian harmonic language which, nevertheless, sometimes echoes the innovations of the likes of Debussy (especially the Intermezzo, 14:02), Ravel and Stravinsky. A fascinating piece of music by one of the 20th Century greats.
I possess several albums of the complete Bartok oeuvres, but this one not . This 1960’s recording session seems to be of of important value,as other/later Bartok releases are a rarety on youtube. I must admit that the sound quality is quite decent for that period.