TITLE: Are there any recordings of Grothendieck online?
QUESTION [18 upvotes]: Illusie mentions tape recordings of Grothendieck explaining his trace formula and more. Are they or similar recordings online? I guess, even if (what I doubt) everything he thought about that is somewhere in print, it would give an interesting insight in his way of thinking.

REPLY [9 votes]: Now you can access the audio lectures that Grothendieck gave at Buffalо in 1973.
Lectures on Topoi
Algebraic geometry
Algebraic groups
Thèmes pour une Harmonie
In the section 1973.
The page is still work in progress.