The singer turned producer extraordinaire has been rehearsing with Yes ahead of the two guest spots.
Trevor Horn is set to join Yes on stage for the first time in 36 years next month.
Horn’s two rare guest appearances will take place at Oxford’s New Theatre on Monday 9th May and London Royal Albert Hall on Tuesday 10th May.
It will be Yes fans’ first opportunity to see Horn performing live with the prog rock legends since the Drama tour way back in 1980.
Horn joined Yes for rehearsal sessions at Rockfield Studios in Monmouth last week where he posed for the above photo with Steve Howe, Alan White, Geoff Downes, Billy Sherwood and Jon Davison.
Yes’ UK tour, which kicks off in Glasgow tomorrow night (27th April), will see them perform ‘Drama’ in full for the first time alongside 1971’s ‘Fragile’ and other anthems from their 48-year back catalogue.
‘Drama’ is the only Yes album to feature Horn on lead vocals following the departure of Jon Anderson. He went on to work with Yes as a producer including 1983’s ‘90125’, 1987’s ‘Big Generator’ and 2011’s ‘Fly from Here’.
Speaking about the upcoming tour, drummer Alan White said: “Reliving those years will be very emotional. I know Chris (Squire, who died in 2015) would have loved to be here with us for this.”
Steve Howe says: “Most of the songs haven’t been performed in some 30 years.”
In other Yes news, former keyboard wizard Rick Wakeman is headlining Stone Free Festival at London’s O2 Arena on Sunday 19th June.
In a world exclusive, Wakeman is performing his snappily titled 1975 album ‘The Myths and Legends of King Arthur and the Knights of the Round Table’ at the show.
Tickets are on sale from Planet Rock Tickets now.