'Gaudete' comes from the Finnish/Swedish 'Piae Cantiones', a collection of religious music from the 16th century. The English folk group 'Steeleye Span' featuring female lead singer Maddy Prior had a hit with this song in the seventies. Peter Martin made a scintillating arrangement for wind-band. By the use of fourths and thirds in the melody the composer harks back to the period from which the song originated (The Middle Ages)