It would have been later than that '83/'84?
Another good venue was the Bass Clef in Hoxton, once saw Alan Holdsworth there, but rammed unlike the DB gig, you literally could hardly get in the door.
Allan Holdsworth was probably the most advanced guitarist on the planet IMHO, his harmonic concepts are still beyond the majority of players, his improvised solos were never the same twice. A truly original talent, one of my all time favourite musicians. RIP.
This old video shows his unique harmonic concepts for guitar and musicality.