I used the Music Studio app for iPhone. Its got a whopping 8000 notes from 30 different instruments in the span of 3 minutes. It's loosely a fan theme for Torbjorn, hence the heavy use of mallet-type sounds to make it sound like he's constructing something in the background.
Art Credit: Check out CAPTAIN (@deercaptain): https://twitter.com/deercaptain?s=09
https://www.instagram.com/kumacap/
Please contact me if you would like to use this in a project. We can discuss the details.