The late King of Pop turned to the Blue singer - whose band have duetted with the likes of Sir Elton John, Stevie Wonder and Angie Stone - for help on knowing when to stop working on a track, and even Simon admits it was ''weird'' for such an iconic performer to seek him out.
Simon said: ''Michael asked, 'When do you know when a song's finished?' Weird him asking my advice, but it was very special.''
The group found working on 'Sorry Seems to be the Hardest Word' with Elton a dream come true and will always value the advice he gave them.
Lee Ryan said: ''As a kid I used to pray I'd sing with Elton John. It was a big ask, but it happened.''
Bandmate Duncan James added: ''He advised us to forget the fancy dance moves. He said we were in a different class to the other boybands and gave us all a gold pendant with our initials.''
Fourth member Antony Costa's favourite memory of the 'All Rise' hitmakers' hey day was meeting his idol George Michael, and he admits he was left heartbroken by the 'Careless Whisper' hitmaker's passing last December.
He told Britain's HELLO! magazine: ''The songs take me back there. Like the time we appeared on 'Top of the Pops' in 2004 and I bumped into my all-time hero, George Michael, who called me his 'fellow North London Greek boy'.
''It has broken my heart that he has left us but I'm so glad I managed to meet him.''
Corgan took to Instagram to confirm rumours of new Pumpkins material, saying the first songs could arrive as early as May.