Complex sentence: Onkyo is also what some people call a form of free improvisation which emerged from Japan in the 1990s typified by small, often quiet, musical gestures, and liberal use of silence.
Split into simpler sentences: Onkyo is also what some people call a form of free improvisation, emerging from Japan in the 1990s. It is typified by small and often quiet musical gestures, and liberal use of silence.