Travelon Gamelon (1977) by Richard Lerman is using piezo-ceramic disks as contact microphones. Many of his works use transducers and his website is a very valuable resource on using these, including a guide for making these microphones.
Apple Box Double (1965) by Pauline Oliveros. This video documents a performance of Pauline Oliveros and Seth Cluett in 2004:
And here another performance of Pauline and Seth on apple boxes, from September 2016:
An interview with Hugh Davies and some music played on the Shozyg (also using some of his egg slicer instruments):
Listen to more Shozyg music:
Several performances of Rainforest (1968-1973) by David Tudor, all using different objects attached to tactile transducers:
Birgit Ulher performing with a small loudspeaker inside the trumpet mute:
Again a piece, which can hardly be documented by a video, since it uses loudspeakers underneath the piano and loudspeakers in the concert hall.
…..sofferte onde serene… (1976) by Luigi Nono:
and part II:
Guai ai gelidi mostri (1983) by Luigi Nono, with live electronics on 10 loudspeakers in the concert hall (of which you won’t hear anything on youtube of course…). A piece to hear live in the concert hall!
A short video showing some of the loudspeakers used in the nowadays Acousmonium of the GRM: