Peter Torbijn of the Netherlands has discovered a film, previously unknown to me and listing only 127 viewings at time of posting, with a brief segment (one minute) of Leonard Cohen singing Sisters of Mercy at the 1970 Aix-en-Provence Festival. The portion featuring Leonard Cohen begins at 2:22.
The description from the site follows:
Sujet consacré au festival de musique pop d’Aix en Provence. Le commentaire sur des images de concerts alterne avec les interviews de festivaliers et du directeur de la manifestation. Le reportage se termine sur des images de Leonard COHEN interprétant “Sisters of Mercy” sur scène.
[via Google Translate] Topic dedicated to pop music festival in Aix en Provence. Commentary on concert pictures alternates with interviews of festival and director of the event. The report concludes with images of Leonard Cohen performing “Sisters of Mercy” on stage.
Update: Véro Chô has offered a summary in English of the initial portion of the video:
This festival of “progressive music” was organised by a general (!) Clément, and while it’s not said explicitly, the idea was met with some resistance it seems. Valery Giscard-d’Estaing (then not yet president, but – I looked it up – minister of Economy and Finance) came to support the general, and the festival opened with him optimistic about its success. The turnout was much lower than expected, with only 15000 people, only half of them paying, on Sunday, when they had expected 100.000 and so the festival ended after two days instead of three. Two spectators from neighbouring villages praise the youth for its peaceful manners and will to emancipate. And the topic ends with a not exactly appreciative comment about Leonard Cohen: the commentator makes a pun on “fausses notes”, which can both mean wrong notes hit by a musician or faults. He says that Leonard Cohen didn’t manage to make forget the wrong notes (i.e. lack of ticket sales). But there’s clearly a double entendre here… The festival lost 1 million French francs, which would be about 200.000 Euros nowadays but must have been a huge sum then.