Question: Which songwriter played the harmonica, John Popper or Philip Oakey?

Context articles: Zygote (album)
Philip Oakey
Philip Oakey &amp; Giorgio Moroder
Together in Electric Dreams
Open Your Heart (The Human League song)
John Popper
Good-Bye Bad Times
The John Popper Project
Be My Lover Now
Louise (The Human League song)

Zygote is the debut studio album by American singer-songwriter John Popper.
 Produced by Terry Manning, it was released on September 7, 1999, less than a month after Popper lost a good friend and fellow bandmember, Bobby Sheehan.
 Accompanying Popper on this album is Carter Beauford (of the Dave Matthews Band) on drums, and Crugie Riccio on guitar, Rob Clores, and Dave Ares (all of Cycomotogoat).
Philip Oakey (born 2 October 1955) is an English singer, songwriter and producer.
 He is best known as the lead singer, songwriter, and co-founder of the English synthpop band The Human League.
 Aside from the Human League, he has had an extensive solo music career and collaborated with numerous other artists and producers.
Philip Oakey & Giorgio Moroder is a collaborative album released in 1985 by Philip Oakey, lead singer of the electronic band The Human League, and seminal electro producer Giorgio Moroder (] ), whose early records had been a major influence on Oakey.
"Together in Electric Dreams" is a song by the British singer and composer Philip Oakey, and Italian composer and producer Giorgio Moroder.
 It was written by Oakey and Moroder and recorded for the original soundtrack of the film "Electric Dreams" (1984).
 It later formed part of the joint album "Philip Oakey & Giorgio Moroder", released in 1985.
 Released as a single in the United Kingdom in September 1984, it proved a major commercial success, even eclipsing the original film it was intended to promote.
 It reached No.3 in the UK Singles Chart, staying in the charts for 13 weeks.
"Open Your Heart" is a song by the British synthpop group The Human League.
 It was released as a single in the UK in September 1981 and peaked at number six in the UK Singles Chart.
 It was written jointly by lead singer Philip Oakey and keyboard player Jo Callis.
 The song features a lead vocal by Oakey and female backing vocals by Susanne Sulley and Joanne Catherall, analogue synthesizers by Jo Callis, Philip Adrian Wright and Ian Burden.
 Drum machines, sequencing and programming were provided by producer Martin Rushent.
John Popper (born March 29, 1967) is an American musician and songwriter.
 He is most famous for his role as frontman of rock band Blues Traveler performing harmonica, guitar, and vocals.
"Good-Bye Bad Times" is a song by the British singer and composer Philip Oakey and producer Giorgio Moroder.
 It was written by Oakey and Moroder and recorded for the album "Philip Oakey & Giorgio Moroder".
 Released as a single in the UK in June 1985 as the follow-up to Oakey and Moroder's 1984 hit "Together In Electric Dreams"; it reached number 44 in the singles charts and remained in the charts for 5 weeks.
 It was moderately successful in Australia, where it peaked at number 26.
The John Popper Project (formal name The John Popper Project Featuring DJ Logic) is an American fusion music group.
 The band's style is a combination of rock, hip hop, and improvisational jazz.
"Be My Lover Now" is a song by the British singer and composer Philip Oakey and producer Giorgio Moroder.
 It was written by Oakey and Moroder and recorded for the album "Philip Oakey & Giorgio Moroder".
 It was released as a single in the UK in August 1985 where it reached number 74 in the singles charts and remained in the charts for 1 week.
 It was the third and final single to be released from the brief Oakey/Moroder partnership which had started with the single "Together in Electric Dreams" (1984).
"Louise" is a song by the British synthpop group The Human League.
 It was released as a single in the UK on 5 November 1984 and peaked at number thirteen in the UK Singles Chart.
 It was written jointly by lead singer Philip Oakey with fellow band members Jo Callis and Philip Adrian Wright.
 The song features a lead vocal by Oakey and female vocals by Susan Ann Sulley and Joanne Catherall, analogue synthesizers by Philip Oakey, Jo Callis, Philip Adrian Wright and Ian Burden.
 The producers were Chris Thomas and Hugh Padgham.
 Although enjoying modest success when released as a single, it appeared on Melody Maker's list of 50 top singles of 1984.