Clarinet Quartet,Woodwind Ensemble Bass Clarinet - Level 3 - Digital Download SKU: A0.781990 By Sia. By Adele Adkins, Christopher Braide, Sia, and Tobias Jesso Jr. Arranged by Aaron Hettinga. Pop. 16 pages. Aaron Hettinga #6035561. Published by Aaron Hettinga (A0.781990). Sia's powerful song Unstoppable is available here arranged for performance by a Clarinet Quartet/Choir. Key of G minor. Follows the form of the original recording, but transposed up ½ step to better accommodate wind instruments.