In 2004, Jason Brown, a mathematics professor at Dalhousie University, published a report titled "Mathematics, Physics and 'A Hard Day's Night'", in which he analysed the properties of the song's opening chord using Fourier transforms. He concluded that Martin's piano contribution provided the important element in the chord beside Harrison's playing. In November the following year, "Wired" published an article on Brown's use of Celemony's Melodyne Editor with Direct Note Access technology to further analyse the chord. Brown's findings were partly challenged in 2012 by another mathematician, Kevin Houston from the University of Leeds. Houston, who also used a Fourier transform, attributed a greater importance in Lennon's contribution on acoustic guitar, rather than the piano notes played by Martin.