The "first 12-note work": Schoenberg's Op. 23, mov. 5, mm. 1-4.
Created by <a href="https://en.wikipedia.org/wiki/User:Hyacinth" class="extiw" title="en:User:Hyacinth">Hyacinth</a> (<a href="https://en.wikipedia.org/wiki/User_talk:Hyacinth" class="extiw" title="en:User talk:Hyacinth">talk</a>) using Sibelius 5.
CC BY-SA 3.0
<span class="int-own-work" lang="en">Own work</span>