Linked from
The 12 pages that link to Extended technique, each with the reason it gives.
Avant-garde musicRelated: They expand instrumental sound beyond standard technique and tone.
Experimental musicRelated: They expand instrumental sound without requiring a new instrument.
Neue MusikRelated: It expands the instrumental vocabulary available to composers.
Unsuk ChinRelated: Her scores often draw on unusual playing methods to expand instrumental color.