Audio Examples 1

Excerpts from compositions (mostly mine)

Elsewhere is a Negative Mirror, for piano with electromagnets – introduction
Includes notes struck by the piano player, each of which activates the electromagnet suspended above, creating the main body of the sound.

Negative Mirror II, for flute, clarinet, violin, cello, percussion, and piano with electromagnets – excerpt 1
This except is provided as a reference for the subsequent example. Though it does include the sound of the electromagnetically-prepared piano, it is the other instruments that are of interest. A recording of these instrumental sounds is played back through the electromagnets at the end of the piece (excerpt 2).

Negative Mirror II – excerpt 2
Drawn from the final moments of the piece. As explained above, a recording of an instrumental section from earlier in the composition is played back through the electromagnets. All sounds heard in this excerpt are created by vibrating piano strings.

Of Dust and Sand – for alto saxophone and piano with electromagnets
In this piece a subset of the electromagnets remains active throughout, the performer physically silencing the strings by pressing down with fingertips. Thus the instrument becomes a kind of anti-piano – lifting a finger frees a string to vibrate, producing sound. In addition, various items, such as paper and a plastic ruler, rest directly on the strings further altering the timbre.
The link under the title above leads to a youtube video that shows the setup fairly well.
Excerpt 1 – mm. 22-51

Excerpt 2 – mm. 65-97

Medusa in Fragments, by Steve Ricks
Steve sent me a few audio files while he was composing this piece, which I ran through the electromagnets. The following files were the results (not all of which made it into his piece). The voice is that of soprano Jennifer Welch-Babidge.
Keep in mind with these – the only things generating sound are the piano strings. Nothing can be heard of the actual original audio files.
Excerpt 1 – spoken voice

Excerpt 2 – the same spoken voice, but with a plastic ruler resting on the piano strings

Excerpt 3 – sung, with some light effects on the original audio file

Excerpt 4 – the same sung passage as above, again with a plastic ruler on the strings