The term "Mechanical Music" is used when, for example, a music track (usually electronic music) is characterized by elements of "mechanical sound design."
"Mechanical sound design" refers to the use of techniques such as time stretching, re-pitching, and looping (typically with very tight or extremely long loop times) in the sound design process.
IMPORTANT: The warping algorithms offered by Ableton Live are originally the main solution for achieving mechanical sound design in its true essence (beats mode, re-pitch).
Example: I take an electronic music track and stretch it to extreme levels (700-800-999 bpm) until I get interesting textures both audibly and creatively, using Ableton warping modes like beats or re-pitch. Then I can chop most interesting parts to obtain Mechanical Music / Mechanical Sound Design