My software couldn't represent chords but one can't whistle in chords anyway! Seperation and recognition of individual notes from semi-quavers to notes of any length longer was achieved. I used a BBC B computer which was very slow compared to present day machines. I was also a record producer in those days and met many 'folkies' who didn't know a crotchet from a hatchet. I designed the device so that they could whistle the tune and the resultant paper copy could be given to, say, backing musicians or arrangers.