When we think of DJs, record decks, CDJs, and USB mixers come to mind - not often reel-to-reel machines! But there are people who have used, and use these vintage machines for mixing. One example is Mr Tape (Modris Skaistkalns) who appears here at the 1991 DMC World Championships Elimination Round at the Hammersmith Palais de Danse in London, England. The set is a remarkable achievement given the physical capability of tape recorders as a mixing tool - though there are presumably no worries about the record skipping!
Mr Tape is not the only one using Reel to reel to mix. Here's Kerri Chandler mixing for resident advisor in 2020:
And here's a live set for Defected Records by Kerri, recorded as recently as last year!
Mix transitions made simple, yet so nifty
And Dreadbox Hypnosis, Circuit Tracks
New UI, devices and tools
AC-DR Drums, when partnerships go bad