Complex sentence: This device was a musical instrument that used live cats arranged into an octave according to the natural timbre of their voices as an instrument, producing music with this instrument resulted from inflicting pain on the animals to they would mew on cue.
Split into simpler sentences: This device was a musical instrument that used live cats arranged into an octave according to the natural timbre of their voices. Performing on it required the player to inflict pain on the animals to they would mew on cue.