docs: music soundcloud link

Author: tlackemann

src/music/index.md

@@ -3,7 +3,8 @@
 A few years back I got really into modular synthesizers. I still am very much interested in the subject but I have had
 far less time to experiment recently.
 
-You can listen to some of my modular recordings on YouTube as [Learning Machines](./learning-machines.md)
+You can listen to some of my modular recordings on YouTube as [Learning Machines](./learning-machines.md) and
+[SoundCloud](https://soundcloud.com/learning-machines).
 
 ## Gear