I caught a glimpse of an animated guy playing a trombone on reddit. This looks like a game akin to Guitar Hero, but the sound... oh, the sound.
What's going on here? The player is racking up points like crazy as he follows the screen directions, but the sound is more like a fifth grader who just picked up a trombone for the first time. Or a dying cow, who can tell? How do they get that sound? Commenters at reddit revealed this is the game Trombone Champ, and guided us to another example.
Aha! You use a mouse or a stylus on a trackpad to produce those notes. If you can call them notes. The game was developed as a parody, with plenty of in-game side quests and jokes, but the real fun is in trying to listen to it. YouTube is full of Trombone Champ clips, some surprisingly good, but most are in the dying cow category. This thread at reddit is full of people wanting to buy the game now, so it's got that going for it.