Embertone Arcane

Embertone Arcane is the most unusual free library on this list because you have to solve puzzles to unlock the sounds. It’s structured as a small adventure game inside Kontakt Player. Five instruments unlock progressively as you solve puzzles, and there’s a bonus alto vocal legato patch that unlocks after everything else. The concept is gimmicky on paper, but I found it pretty fun in practice. I probably just enjoy playing puzzle games too much.

The library itself is more than 2 GB of high-quality samples, some sourced from Embertone’s paid products and some exclusive to Arcane. If you want to bypass the game, the individual patches can be accessed through the Library browser directly, which Embertone leaves open as a spoiler-friendly option.