When Glasgow was Cultural capital of Europe (1990), John made a rather peculiar contribution in an empty theater, together with saxophone player. If I remember correctly it might have been Send Me One Line. It was probably a rehearsal as John did play Send Me One Line during the Big Day (Sunday 3 June). This was at Custom House Quay in the bandstand along the river Clyde. The multi stage show was broadcast live by Channel 4.
The cameraman zooms in on John's sunglasses that reflect the audience and there are also helicopter shots.
The Glasgow Herald announced: (23 March 1990)
Culture city musicians to raise funds for homeless
The Big Day, Music from the Heart of Glasgow, is the full title of a free day-long event designed to raise awareness and solicit donations on behalf of Glasgow's young, single homeless. Six hours' worth of the capital of culture's largest undertaking will be screened live on Channel 4, four hours in the afternoon, two hours in the evening.
The big names confirmed so far include such top Scottish rock performers as Deacon Blue, Hue and Cry, the Average White Band, Eddi Reader, and Jimmy Somerville. The widest range of tastes will be catered for in performances by the Scottish Chamber Orchestra, John Martyn and Tommy Smith.
Dublin's Hothouse Flowers will play in George Square, the focus for a musical meeting between local Glasgow groups and bands from the Irish capital. The other sites, all in simultaneous action, will be at Custom House Quay (for folk, jazz and accoustic music), near the People's Palace on Glasgow Green (world music), and at Flesher's Haugh, the venue for the evening's big rock concert at which an attendance in excess of 100,000 is anticipated.
And further on:
Organisers of The Big Day of music and street parties in Glasgow on Sunday 3 June said they were confident that spectators' safety would not be compromised, despite an anticipated attendance of more than 150,000 at four main venues. At Custom House Quay, the River Detectives, Billy Bragg, and John Martyn will entertain.