In 1908, inspired by both their own interest in folk music and by the contemporary resurgence of interest in traditional national culture, Bartok and Kodaly undertook an expedition into the countryside to collect and research old Magyar folk melodies. Their findings came as somewhat of a surprise: previously, most people had considered real Magyar folk music to be Gypsy music. The classic example of this misperception is Franz Liszt's famous Hungarian Rhapsodies for piano, which were actually based on popular Gypsy tunes of the time.

In contrast, the old Magyar folk melodies discovered by Bartok and Kodaly bore little if any resemblance to the popular music of the Gypsies. Instead, the songs they found were almost all based on pentatonic scales similar to those found in various Oriental folk traditions, notably those of Central Asia and Siberia. (Indeed, Kodaly later discovered striking parallels between some ancient Magyar songs and songs of the Mari and Chuvash peoples of north-eastern Russia.)

Bartok and Kodaly quickly set about incorporating elements of this real Magyar peasant music into their compositions. While Kodaly would frequently quote folk songs verbatim and write pieces derived entirely from authentic folk melodies, Bartok's style was more of a synthesis of folk music, classicism, and modernism. He rarely used actual peasant melodies in his compositions, but his melodic and harmonic sense was still profoundly influenced by the folk music of Hungary and Romania, and he was very fond of the asymmetrical dance rhythms and pungent harmonies found in Bulgarian music.