Tonal colour in Expressionism

Tonal colour became one of the most important dimensions of music. New means of expression were sought by using instruments at the extremities of their ranges or by inventing new playing techniques. Arnold Schönberg developed a half-speaking, half-singing mode of vocal expression known as Sprechgesang.

I can tell you, dearest friend, that if it became known how much friendship, love and a world of human and spiritual references I have smuggled into these three movements, the adherents of programme music – should there be any left – would go mad with joy. –Alban Berg